docs(installation): add playground links

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

@@ -3,6 +3,10 @@ title: Installation
 description: 'Learn how to install and configure Nuxt UI in your Nuxt application.'
 framework: nuxt
 module: ui
+links:
+  - label: Playground
+    to: https://codesandbox.io/p/devbox/nuxt-ui3-n3sxks
+    icon: i-lucide-codesandbox
 ---
 
 ::callout{to="/getting-started/installation/vue" icon="i-logos-vue" class="hidden"}