docs: format installation commands for madkrown code block (anomalyco#4151)

Co-authored-by: GitHub Action <action@github.com>

Author: wan-kong

packages/web/src/content/docs/index.mdx

@@ -42,11 +42,31 @@ You can also install it with the following commands:
 - **Using Node.js**
 
   <Tabs>
-    <TabItem label="npm">```bash npm install -g opencode-ai ```</TabItem>
-    <TabItem label="Bun">```bash bun install -g opencode-ai ```</TabItem>
-    <TabItem label="pnpm">```bash pnpm install -g opencode-ai ```</TabItem>
-    <TabItem label="Yarn">```bash yarn global add opencode-ai ```</TabItem>
-  </Tabs>
+  <TabItem label="npm">
+    ```bash 
+    npm install -g opencode-ai 
+    ```
+
+    </TabItem>
+  <TabItem label="Bun">
+    ```bash 
+    bun install -g opencode-ai 
+    ```
+
+    </TabItem>
+  <TabItem label="pnpm">
+    ```bash 
+    pnpm install -g opencode-ai 
+    ```
+
+    </TabItem>
+  <TabItem label="Yarn">
+    ```bash 
+    yarn global add opencode-ai 
+    ```
+    
+  </TabItem>
+</Tabs>
 
 - **Using Homebrew on macOS and Linux**