docs: use lang="ts" everywhere

docs/content/1.getting-started/2.installation.md

@@ -206,7 +206,7 @@ An example SFC using IntelliSense (note the `/*ui*/` prefix, also works with `re
   <UCard :ui="ui" />
 </template>
 
-<script setup>
+<script setup lang="ts">
 const ui = /*ui*/ {
   background: 'bg-white dark:bg-slate-900'
 }

docs/content/1.getting-started/3.theming.md

@@ -247,7 +247,7 @@ You can easily build a color mode button by using the `useColorMode` composable
 
 #code
 ```vue
-<script setup>
+<script setup lang="ts">
 const colorMode = useColorMode()
 const isDark = computed({
   get () {

docs/content/1.getting-started/4.shortcuts.md

@@ -130,7 +130,7 @@ defineShortcuts({
 To display shortcuts in your app according to the user's OS, you can use the `useShortcuts` composable.
 
 ```vue
-<script setup>
+<script setup lang="ts">
 const { metaSymbol } = useShortcuts()
 </script>