Replaced the static navigation with a dynamic, internationalized dropdown menu powered by a new `useNavLinks` composable. The
navigation items are now sourced from i18n files. The featured project cards on the homepage have been refactored to use the
`<UPageCard>` component, and the content schema is updated with `spotlight` and `highlight` options for enhanced display.
This commit refactors the index page to source its content from @nuxt/content, replacing the previous implementation that used i18n
JSON files and hardcoded data within the component.
Key changes:
- Introduced `content.config.ts` to define collections and Zod schemas for type-safe content.
- Moved page content into localized YAML files (`content/en-US/index.yml` and `content/zh-CN/index.yml`).
- Updated `app/pages/index.vue` to fetch data dynamically using `useAsyncData` and `queryCollection`.
- Removed redundant content from i18n JSON files and the Vue component script.
This change decouples content from presentation, improves maintainability, and centralizes content management.
