docs: switch between v2 and v3 docs

Author: farnabaz

docs/app/components/AppHeader.vue

@@ -30,12 +30,25 @@ defineShortcuts({
       >
         <AppLogo class="w-auto h-6 shrink-0" />
 
-        <UBadge
-          :label="`v${config.version}`"
-          variant="subtle"
-          size="sm"
-          class="hidden -mb-[2px] font-semibold sm:inline-block truncate"
-        />
+        <UDropdownMenu
+          v-slot="{ open }"
+          :modal="false"
+          :items="[{ label: `v${config.version}`, active: true, color: 'primary', checked: true, type: 'checkbox' }, { label: 'v2.13.4', to: 'https://content.nuxt.com' }]"
+          :ui="{ content: 'w-(--radix-dropdown-menu-trigger-width) min-w-0' }"
+          size="xs"
+        >
+          <UButton
+            :label="`v${config.version}`"
+            variant="subtle"
+            trailing-icon="i-lucide-chevron-down"
+            size="xs"
+            class="-mb-[3px] font-semibold rounded-full truncate"
+            :class="[open && 'bg-[var(--ui-primary)]/15 ']"
+            :ui="{
+              trailingIcon: ['transition-transform duration-200', open ? 'rotate-180' : undefined].filter(Boolean).join(' '),
+            }"
+          />
+        </UDropdownMenu>
       </NuxtLink>
     </template>