diff --git a/docs/src/demos/Extensions/Bold/index.spec.js b/docs/src/demos/Extensions/Bold/index.spec.js
index 8d54f47b..b80b0a33 100644
--- a/docs/src/demos/Extensions/Bold/index.spec.js
+++ b/docs/src/demos/Extensions/Bold/index.spec.js
@@ -29,5 +29,17 @@ context('/api/extensions/bold', () => {
       cy.get('.ProseMirror').type('{meta}b', {force: true}).type('{meta}b', {force: true})
       cy.get('.ProseMirror strong').should('not.exist')
     })
+
+    it('should make a bold text from the default markdown shortcut', () => {
+      cy.get('.ProseMirror')
+        .type('**Bold**', {force: true})
+        .contains('strong', 'Bold')
+    })
+
+    it('should make a bold text from the alternative markdown shortcut', () => {
+      cy.get('.ProseMirror')
+        .type('__Bold__', {force: true})
+        .contains('strong', 'Bold')
+    })
   })
 })
\ No newline at end of file
diff --git a/docs/src/demos/Extensions/HorizontalRule/index.spec.js b/docs/src/demos/Extensions/HorizontalRule/index.spec.js
new file mode 100644
index 00000000..96c0fdb7
--- /dev/null
+++ b/docs/src/demos/Extensions/HorizontalRule/index.spec.js
@@ -0,0 +1,40 @@
+context('/api/extensions/horizontal-rule', () => {
+  beforeEach(() => {
+    cy.visit('/api/extensions/horizontal-rule')
+
+    cy.get('.ProseMirror').window().then(window => {
+      const { editor } = window
+      editor.setContent('<p>Example Text</p>')
+    })
+  })
+
+  describe('horizontal-rule', () => {
+    it('the button should add a horizontal rule', () => {
+      cy.get('.ProseMirror hr').should('not.exist')
+      cy.get('.demo__preview button:first').click({ force: true })
+      cy.get('.ProseMirror hr').should('exist')
+    })
+
+    it('the default markdown shortcut should add a horizontal rule', () => {
+      cy.get('.ProseMirror').window().then(window => {
+        const { editor } = window
+        editor.clearContent()
+
+        cy.get('.ProseMirror hr').should('not.exist')
+        cy.get('.ProseMirror').type('---', {force: true})
+        cy.get('.ProseMirror hr').should('exist')
+      })
+    })
+
+    it('the alternative markdown shortcut should add a horizontal rule', () => {
+      cy.get('.ProseMirror').window().then(window => {
+        const { editor } = window
+        editor.clearContent()
+
+        cy.get('.ProseMirror hr').should('not.exist')
+        cy.get('.ProseMirror').type('___ ', {force: true})
+        cy.get('.ProseMirror hr').should('exist')
+      })
+    })
+  })
+})
\ No newline at end of file
diff --git a/docs/src/demos/Extensions/HorizontalRule/index.vue b/docs/src/demos/Extensions/HorizontalRule/index.vue
new file mode 100644
index 00000000..563169fe
--- /dev/null
+++ b/docs/src/demos/Extensions/HorizontalRule/index.vue
@@ -0,0 +1,54 @@
+<template>
+  <div v-if="editor">
+    <button @click="editor.focus().horizontalRule()">
+      horizontalRule
+    </button>
+
+    <editor-content :editor="editor" />
+  </div>
+</template>
+
+<script>
+import { Editor } from '@tiptap/core'
+import { EditorContent } from '@tiptap/vue'
+import Document from '@tiptap/extension-document'
+import Paragraph from '@tiptap/extension-paragraph'
+import Text from '@tiptap/extension-text'
+import HorizontalRule from '@tiptap/extension-horizontal-rule'
+
+export default {
+  components: {
+    EditorContent,
+  },
+
+  data() {
+    return {
+      editor: null,
+    }
+  },
+
+  mounted() {
+    this.editor = new Editor({
+      extensions: [
+        Document(),
+        Paragraph(),
+        Text(),
+        HorizontalRule(),
+      ],
+      content: `
+        <p>This is a paragraph.</p>
+        <hr>
+        <p>And this is another paragraph.</p>
+        <hr>
+        <p>But between those paragraphs are horizontal rules.</p>
+      `,
+    })
+
+    window.editor = this.editor
+  },
+
+  beforeDestroy() {
+    this.editor.destroy()
+  }
+}
+</script>
\ No newline at end of file
diff --git a/docs/src/demos/Extensions/Strike/index.spec.js b/docs/src/demos/Extensions/Strike/index.spec.js
index 31e421c6..4c931953 100644
--- a/docs/src/demos/Extensions/Strike/index.spec.js
+++ b/docs/src/demos/Extensions/Strike/index.spec.js
@@ -32,7 +32,7 @@ context('/api/extensions/strike', () => {
 
     it('should make a striked text from the markdown shortcut', () => {
       cy.get('.ProseMirror')
-        .type('~~Strike~~', {force: true})
+        .type('~Strike~', {force: true})
         .contains('s', 'Strike')
     })
   })
diff --git a/docs/src/demos/Extensions/Underline/index.spec.js b/docs/src/demos/Extensions/Underline/index.spec.js
new file mode 100644
index 00000000..c1eb33ce
--- /dev/null
+++ b/docs/src/demos/Extensions/Underline/index.spec.js
@@ -0,0 +1,33 @@
+context('/api/extensions/underline', () => {
+  beforeEach(() => {
+    cy.visit('/api/extensions/underline')
+
+    cy.get('.ProseMirror').window().then(window => {
+      const { editor } = window
+      editor.setContent('<p>Example Text</p>')
+      editor.focus().selectAll()
+    })
+  })
+
+  describe('bold', () => {
+    it('the button should underline the selected text', () => {
+      cy.get('.demo__preview button:first').click({ force: true })
+      cy.get('.ProseMirror').contains('u', 'Example Text')
+    })
+
+    it('the button should toggle the selected text underline', () => {
+      cy.get('.demo__preview button:first').dblclick({ force: true })
+      cy.get('.ProseMirror u').should('not.exist')
+    })
+
+    it('the keyboard shortcut should underline the selected text', () => {
+      cy.get('.ProseMirror').type('{meta}u', {force: true})
+      cy.get('.ProseMirror').contains('u', 'Example Text')
+    })
+
+    it('the keyboard shortcut should toggle the selected text underline', () => {
+      cy.get('.ProseMirror').type('{meta}u', {force: true}).type('{meta}u', {force: true})
+      cy.get('.ProseMirror u').should('not.exist')
+    })
+  })
+})
\ No newline at end of file
diff --git a/docs/src/demos/Extensions/Underline/index.vue b/docs/src/demos/Extensions/Underline/index.vue
new file mode 100644
index 00000000..558d09cc
--- /dev/null
+++ b/docs/src/demos/Extensions/Underline/index.vue
@@ -0,0 +1,52 @@
+<template>
+  <div v-if="editor">
+    <button @click="editor.focus().underline()" :class="{ 'is-active': editor.isActive('underline') }">
+      underline
+    </button>
+
+    <editor-content :editor="editor" />
+  </div>
+</template>
+
+<script>
+import { Editor } from '@tiptap/core'
+import { EditorContent } from '@tiptap/vue'
+import Document from '@tiptap/extension-document'
+import Paragraph from '@tiptap/extension-paragraph'
+import Text from '@tiptap/extension-text'
+import Underline from '@tiptap/extension-underline'
+
+export default {
+  components: {
+    EditorContent,
+  },
+
+  data() {
+    return {
+      editor: null,
+    }
+  },
+
+  mounted() {
+    this.editor = new Editor({
+      extensions: [
+        Document(),
+        Paragraph(),
+        Text(),
+        Underline(),
+      ],
+      content: `
+        <p>There is no underline here.</p>
+        <p><u>This is underlined though.</u></p>
+        <p style="text-decoration: underline">And this as well.</p>
+      `,
+    })
+
+    window.editor = this.editor
+  },
+
+  beforeDestroy() {
+    this.editor.destroy()
+  }
+}
+</script>
\ No newline at end of file
diff --git a/docs/src/docPages/api/extensions/blockquote.md b/docs/src/docPages/api/extensions/blockquote.md
index b6d4e9c8..392fb229 100644
--- a/docs/src/docPages/api/extensions/blockquote.md
+++ b/docs/src/docPages/api/extensions/blockquote.md
@@ -1,7 +1,7 @@
 # Blockquote
 The Blockquote extension enables you to use the `<blockquote>` HTML tag in the editor. This is great – you might have guessed – to use quotes in the editor.
 
-Type `> ` on the beginning of a new line and it will be magically transformed to a blockquote.
+Type `> ` at the beginning of a new line and it will be magically transformed to a blockquote.
 
 ## Options
 | Option | Type   | Default | Description                                  |
diff --git a/docs/src/docPages/api/extensions/bold.md b/docs/src/docPages/api/extensions/bold.md
index a98ef14e..81f28cf8 100644
--- a/docs/src/docPages/api/extensions/bold.md
+++ b/docs/src/docPages/api/extensions/bold.md
@@ -1,5 +1,5 @@
 # Bold
-This extension is used to render text in **bold**. If you pass `<strong>`, `<b>` tags, or text with inline `style` attributes setting the `font-weight` CSS rule in the editor’s initial content, they all will be rendered accordingly.
+Use this extension to render text in **bold**. If you pass `<strong>`, `<b>` tags, or text with inline `style` attributes setting the `font-weight` CSS rule in the editor’s initial content, they all will be rendered accordingly.
 
 Type `**two asterisks**` or `__two underlines__` and the it will be magically transformed to **bold** text while you type.
 
diff --git a/docs/src/docPages/api/extensions/horizontal-rule.md b/docs/src/docPages/api/extensions/horizontal-rule.md
index 5c64e87f..616ada6e 100644
--- a/docs/src/docPages/api/extensions/horizontal-rule.md
+++ b/docs/src/docPages/api/extensions/horizontal-rule.md
@@ -1,5 +1,7 @@
 # HorizontalRule
-Enables you to use the `<hr>` HTML tag in the editor.
+Use this extension to render a `<hr>` HTML tag. If you pass `<hr>` in the editor’s initial content, it’ll be rendered accordingly.
+
+Type `---` (three dashes) or `___ ` (three underscores and a space) at the beginning of a new line and it will be magically transformed to a horizontal rule.
 
 ## Options
 | Option | Type   | Default | Description                                  |
@@ -9,11 +11,17 @@ Enables you to use the `<hr>` HTML tag in the editor.
 ## Commands
 | Command         | Options | Description               |
 | --------------- | ------- | ------------------------- |
-| horizontal_rule | —       | Create a horizontal rule. |
+| horizontalRule | —       | Create a horizontal rule. |
 
 ## Keyboard shortcuts
 *None*
 
+## Source Code
+[packages/extension-horizontal-rule/](https://github.com/ueberdosis/tiptap-next/blob/main/packages/extension-horizontal-rule/)
+
+## Usage
+<demo name="Extensions/HorizontalRule" highlight="3-5,17,36" />
+
 ## Usage
 ```markup
 <template>
diff --git a/docs/src/docPages/api/extensions/italic.md b/docs/src/docPages/api/extensions/italic.md
index e566ed22..398f725e 100644
--- a/docs/src/docPages/api/extensions/italic.md
+++ b/docs/src/docPages/api/extensions/italic.md
@@ -1,5 +1,5 @@
 # Italic
-This extension is used to render text in *italic*. If you pass `<em>`, `<i>` tags, or text with inline `style` attributes setting `font-style: italic` in the editor’s initial content, they all will be rendered accordingly.
+Use this extension to render text in *italic*. If you pass `<em>`, `<i>` tags, or text with inline `style` attributes setting `font-style: italic` in the editor’s initial content, they all will be rendered accordingly.
 
 ::: warning Restrictions
 The extension will generate the corresponding `<em>` HTML tags when reading contents of the `Editor` instance. All text marked italic, regardless of the method will be normalized to `<em>` HTML tags.
diff --git a/docs/src/docPages/api/extensions/strike.md b/docs/src/docPages/api/extensions/strike.md
index 57b5096d..36913e65 100644
--- a/docs/src/docPages/api/extensions/strike.md
+++ b/docs/src/docPages/api/extensions/strike.md
@@ -1,7 +1,7 @@
 # Strike
-This extension is used to render ~~striked text~~. If you pass `<s>`, `<del>`, `<strike>` tags, or text with inline `style` attributes setting `text-decoration: line-through` in the editor’s initial content, they all will be rendered accordingly.
+Use this extension to render ~~striked text~~. If you pass `<s>`, `<del>`, `<strike>` tags, or text with inline `style` attributes setting `text-decoration: line-through` in the editor’s initial content, they all will be rendered accordingly.
 
-Type `~~two tildes~~` and the it will be magically ~~striked through~~ while you type.
+Type `~text between tildes~` and it will be magically ~~striked through~~ while you type.
 
 ::: warning Restrictions
 The extension will generate the corresponding `<s>` HTML tags when reading contents of the `Editor` instance. All text striked through, regardless of the method will be normalized to `<s>` HTML tags.
diff --git a/docs/src/docPages/api/extensions/underline.md b/docs/src/docPages/api/extensions/underline.md
index 3c4c57d5..ab27c3ce 100644
--- a/docs/src/docPages/api/extensions/underline.md
+++ b/docs/src/docPages/api/extensions/underline.md
@@ -1,5 +1,9 @@
 # Underline
-Enables you to use the `<u>` HTML tag in the editor.
+Use this extension to render text <u>underlined</u>. If you pass `<u>` tags, or text with inline `style` attributes setting `text-decoration: underline` in the editor’s initial content, they all will be rendered accordingly.
+
+::: warning Restrictions
+The extension will generate the corresponding `<u>` HTML tags when reading contents of the `Editor` instance. All text marked underlined, regardless of the method will be normalized to `<u>` HTML tags.
+:::
 
 ## Options
 | Option | Type   | Default | Description                                  |
@@ -15,45 +19,8 @@ Enables you to use the `<u>` HTML tag in the editor.
 * Windows & Linux: `Control` + `U`
 * macOS: `Command` + `U`
 
+## Source Code
+[packages/extension-underline/](https://github.com/ueberdosis/tiptap-next/blob/main/packages/extension-underline/)
+
 ## Usage
-```markup
-<template>
-  <div>
-    <editor-menu-bar :editor="editor" v-slot="{ commands, isActive }">
-      <button type="button" :class="{ 'is-active': isActive.underline() }" @click="commands.underline">
-        Underline
-      </button>
-    </editor-menu-bar>
-
-    <editor-content :editor="editor" />
-  </div>
-</template>
-
-<script>
-import { Editor, EditorContent, EditorMenuBar } from 'tiptap'
-import { Underline } from 'tiptap-extensions'
-
-export default {
-  components: {
-    EditorMenuBar,
-    EditorContent,
-  },
-  data() {
-    return {
-      editor: new Editor({
-        extensions: [
-          Underline(),
-        ],
-        content: `
-          <p><u>This is underlined.</u></p>
-          <p style="text-decoration: underline">This as well.</p>
-        `,
-      }),
-    }
-  },
-  beforeDestroy() {
-    this.editor.destroy()
-  }
-}
-</script>
-```
\ No newline at end of file
+<demo name="Extensions/Underline" highlight="3-5,17,36" />
\ No newline at end of file
diff --git a/docs/src/links.yaml b/docs/src/links.yaml
index 35970fcd..88e76cc3 100644
--- a/docs/src/links.yaml
+++ b/docs/src/links.yaml
@@ -184,7 +184,6 @@
         #   draft: true
         - title: Underline
           link: /api/extensions/underline
-          draft: true
     - title: Commands
       link: /api/commands
       draft: true