docs: add an example of provide with object syntax plugins (#24993)

docs/2.guide/2.directory-structure/1.plugins.md

@@ -157,6 +157,7 @@ Normally, Vue.js composables are bound to the current component instance while p
 
 If you would like to provide a helper on the [`NuxtApp`](/docs/api/composables/use-nuxt-app) instance, return it from the plugin under a `provide` key.
 
+::code-group
 ```ts [plugins/hello.ts]
 export default defineNuxtPlugin(() => {
   return {
@@ -166,6 +167,19 @@ export default defineNuxtPlugin(() => {
   }
 })
 ```
+```ts [plugins/hello-object-syntax.ts]
+export default defineNuxtPlugin({
+  name: 'hello',
+  setup () {
+    return {
+      provide: {
+        hello: (msg: string) => `Hello ${msg}!`
+      }
+    }
+  }
+})
+```
+::
 
 You can then use the helper in your components: