fix(docs): update CardGrid import path

- Change import path from @astrojs/light/components to @astrojs/starlight/components

Author: fulleni

src/content/docs/customization/index.mdx

@@ -2,7 +2,7 @@
 title: 'Customization Guides'
 description: Learn how to modify the shared packages to customize your applications.
 ---
-import { Card, CardGrid } from '@astrojs/light/components';
+import { Card, CardGrid } from '@astrojs/starlight/components';
 
 This section provides practical, hands-on guides for customizing the toolkit by modifying the shared packages. Following these guides is the key to unlocking the full potential of the source code.