docs: embed playground

docs/pages/playground.vue

@@ -0,0 +1,24 @@
+<script setup>
+const title = 'Playground'
+const description = 'Play online with our interactive Nuxt Image playground.'
+
+useSeoMeta({
+  title,
+  ogTitle: 'Nuxt UI Playground',
+  description
+})
+
+defineOgImage({
+  component: 'Docs',
+  title,
+  description
+})
+</script>
+
+<template>
+  <div class="h-[calc(100vh-var(--header-height))]">
+    <ClientOnly>
+      <iframe :src="`https://stackblitz.com/edit/nuxt-ui?embed=1&file=app.config.ts,app.vue&theme=${$colorMode.preference}`" width="100%" height="100%" />
+    </ClientOnly>
+  </div>
+</template>