Add documentation about available MDX components

Co-authored-by: huangyiirene <7665279+huangyiirene@users.noreply.github.com>

Author: Copilot

example/content/docs/configuration.mdx

@@ -97,6 +97,18 @@ description: Page description for SEO
 - **title**: Page title (required)
 - **description**: Page description for SEO (required)
 
+### Available Components
+
+ObjectDocs provides Fumadocs UI components globally. No imports needed:
+
+- **Callout**: `<Callout type="info|warn|error">...</Callout>`
+- **Cards/Card**: `<Cards><Card title="..." icon="...">...</Card></Cards>`
+- **Steps/Step**: `<Steps><Step>...</Step></Steps>`
+- **Tabs/Tab**: For tabbed content
+
+Example:
+
+```mdx
 <Callout type="warn">
 Always include both `title` and `description` in your frontmatter for proper SEO and navigation.
 </Callout>

example/content/docs/getting-started.mdx

@@ -80,6 +80,7 @@ pnpm dev
 
 Visit [http://localhost:7777](http://localhost:7777) to see your site.
 
+{/* Note: Callout, Cards, Steps and other Fumadocs components are globally available */}
 <Callout type="info">
 The development server includes hot reload, so changes to your content will be reflected immediately.
 </Callout>

example/content/docs/index.mdx

@@ -17,6 +17,7 @@ ObjectDocs is a next-generation documentation engine built on:
 
 ## Key Features
 
+{/* ObjectDocs provides Fumadocs components globally - no imports needed */}
 <Cards>
   <Card title="Metadata-Driven" icon="settings">
     Control navigation, sidebars, and SEO entirely via JSON configuration files.