add useEditor to docs

docs/src/docPages/installation/vue3.md

@@ -75,6 +75,34 @@ export default {
 </script>
 ```
 
+Alternatively, you can use the Composition API with the `useEditor` method.
+
+```html
+<template>
+  <editor-content :editor="editor" />
+</template>
+
+<script>
+import { useEditor, EditorContent } from '@tiptap/vue-3'
+import { defaultExtensions } from '@tiptap/starter-kit'
+
+export default {
+  components: {
+    EditorContent,
+  },
+
+  setup() {
+    const editor = useEditor({
+      content: '<p>I’m running tiptap with Vue.js. 🎉</p>',
+      extensions: defaultExtensions(),
+    })
+
+    return { editor }
+  },
+}
+</script>
+```
+
 ## 4. Add it to your app
 Now, let’s replace the content of `src/App.vue` with the following example code to use our new `Tiptap` component in our app.