add more content to the heading page

docs/src/docPages/api/extensions/heading.md

@@ -20,53 +20,8 @@ Enables you to use headline HTML tags in the editor.
 * `Control` + `Shift` + `5` → H5
 * `Control` + `Shift` + `6` → H6
 
+## Source Code
+[packages/extension-heading/](https://github.com/ueberdosis/tiptap-next/blob/main/packages/extension-heading/)
+
 ## Usage
-```markup
-<template>
-  <div>
-    <editor-menu-bar :editor="editor" v-slot="{ commands, isActive }">
-      <div>
-        <button type="button" :class="{ 'is-active': isActive.heading({ level: 1 }) }" @click="commands.heading({ level: 1})">
-          H1
-        </button>
-        <button type="button" :class="{ 'is-active': isActive.heading({ level: 2 }) }" @click="commands.heading({ level: 2 })">
-          H2
-        </button>
-      </div>
-    </editor-menu-bar>
-
-    <editor-content :editor="editor" />
-  </div>
-</template>
-
-<script>
-import { Editor, EditorContent, EditorMenuBar } from 'tiptap'
-import { Heading } from 'tiptap-extensions'
-
-export default {
-  components: {
-    EditorMenuBar,
-    EditorContent,
-  },
-  data() {
-    return {
-      editor: new Editor({
-        extensions: [
-          Heading({
-            levels: [1, 2],
-          }),
-        ],
-        content: `
-          <h1>This is a headline level 1</h1>
-          <h2>This is a headline level 2</h2>
-          <h3>This headline will be converted to a paragraph, because it's not defined in the levels option.</h3>
-        `,
-      }),
-    }
-  },
-  beforeDestroy() {
-    this.editor.destroy()
-  }
-}
-</script>
-```
+<demo name="Extensions/Heading" highlight="" />