feat(content): add initial homepage content and navigation

This commit introduces the foundational content and navigation for the website's homepage.

- Adds a new navigation menu to the default layout, linking to Services, Projects, and Insights.
- Creates YAML content files for the homepage in both English (en) and Chinese (zh-CN).
- Populates the content with key sections including capabilities, featured projects, and tech stack.

app/layouts/default.vue

@@ -2,6 +2,12 @@
   <UPage>
     <UHeader>
       <template #title> Tootaio Studio </template>
+      <template #default>
+        <UNavigationMenu :items="navLinks" variant="link" />
+      </template>
+      <template #body>
+        <UNavigationMenu :items="navLinks" orientation="vertical" />
+      </template>
       <template #right>
         <UColorModeButton />
         <UButton