docs: add version select (#532)

docs/error.vue

@@ -21,6 +21,8 @@
 <script setup lang="ts">
 import type { NuxtError } from '#app'
 
+const { prefix, removePrefixFromNavigation, removePrefixFromFiles } = useContentSource()
+
 useSeoMeta({
   title: 'Page not found',
   description: 'We are sorry but this page could not be found.'
@@ -30,14 +32,26 @@ defineProps<{
   error: NuxtError
 }>()
 
-const { data: navigation } = await useAsyncData('navigation', () => fetchContentNavigation(), {
-  default: () => []
+const { data: navigation } = await useLazyAsyncData('navigation', () => fetchContentNavigation(), {
+  default: () => [],
+  transform: (navigation) => {
+    navigation = navigation.find(link => link._path === prefix.value)?.children || []
+
+    return prefix.value === '/main' ? removePrefixFromNavigation(navigation) : navigation
+  }
 })
+
 const { data: files } = await useLazyAsyncData('files', () => queryContent().where({ _type: 'markdown', navigation: { $ne: false } }).find(), {
-  default: () => []
+  default: () => [],
+  transform: (files) => {
+    files = files.filter(file => file._path.startsWith(prefix.value))
+
+    return prefix.value === '/main' ? removePrefixFromFiles(files) : files
+  }
 })
 
 // Provide
 
 provide('navigation', navigation)
+provide('files', files)
 </script>