docs: remove Yarn instructions

docs/api/marks/bold.md

@@ -17,11 +17,7 @@ The extension will generate the corresponding `<strong>` HTML tags when reading
 
 ## Installation
 ```bash
-# with npm
 npm install @tiptap/extension-bold
-
-# with Yarn
-yarn add @tiptap/extension-bold
 ```
 
 ## Settings

docs/api/marks/code.md

@@ -13,11 +13,7 @@ Type something with <code>\`back-ticks around\`</code> and it will magically tra
 
 ## Installation
 ```bash
-# with npm
 npm install @tiptap/extension-code
-
-# with Yarn
-yarn add @tiptap/extension-code
 ```
 
 ## Settings

docs/api/marks/highlight.md

@@ -13,11 +13,7 @@ Type `==two equal signs==` and it will magically transform to <mark>highlighted<
 
 ## Installation
 ```bash
-# with npm
 npm install @tiptap/extension-highlight
-
-# with Yarn
-yarn add @tiptap/extension-highlight
 ```
 
 ## Settings

docs/api/marks/italic.md

@@ -17,11 +17,7 @@ The extension will generate the corresponding `<em>` HTML tags when reading cont
 
 ## Installation
 ```bash
-# with npm
 npm install @tiptap/extension-italic
-
-# with Yarn
-yarn add @tiptap/extension-italic
 ```
 
 ## Settings

docs/api/marks/link.md

@@ -15,11 +15,7 @@ Pasted URLs will be transformed to links automatically.
 
 ## Installation
 ```bash
-# with npm
 npm install @tiptap/extension-link
-
-# with Yarn
-yarn add @tiptap/extension-link
 ```
 
 ## Settings

docs/api/marks/strike.md

@@ -17,11 +17,7 @@ The extension will generate the corresponding `<s>` HTML tags when reading conte
 
 ## Installation
 ```bash
-# with npm
 npm install @tiptap/extension-strike
-
-# with Yarn
-yarn add @tiptap/extension-strike
 ```
 
 ## Settings

docs/api/marks/subscript.md

@@ -11,11 +11,7 @@ Use this extension to render text in <sub>subscript</sub>. If you pass `<sub>` o
 
 ## Installation
 ```bash
-# with npm
 npm install @tiptap/extension-subscript
-
-# with Yarn
-yarn add @tiptap/extension-subscript
 ```
 
 ## Settings

docs/api/marks/superscript.md

@@ -11,11 +11,7 @@ Use this extension to render text in <sup>superscript</sup>. If you pass `<sup>`
 
 ## Installation
 ```bash
-# with npm
 npm install @tiptap/extension-superscript
-
-# with Yarn
-yarn add @tiptap/extension-superscript
 ```
 
 ## Settings

docs/api/marks/text-style.md

@@ -11,11 +11,7 @@ This mark renders a `<span>` HTML tag and enables you to add a list of styling r
 
 ## Installation
 ```bash
-# with npm
 npm install @tiptap/extension-text-style
-
-# with Yarn
-yarn add @tiptap/extension-text-style
 ```
 
 ## Commands

docs/api/marks/underline.md

@@ -17,11 +17,7 @@ The extension will generate the corresponding `<u>` HTML tags when reading conte
 
 ## Installation
 ```bash
-# with npm
 npm install @tiptap/extension-underline
-
-# with Yarn
-yarn add @tiptap/extension-underline
 ```
 
 ## Settings