add toc demo

docs/src/demos/Guide/NodeViews/TableOfContents/index.vue

@@ -0,0 +1,48 @@
+<template>
+  <div v-if="editor">
+    <editor-content :editor="editor" />
+  </div>
+</template>
+
+<script>
+import { Editor, EditorContent, defaultExtensions } from '@tiptap/vue-starter-kit'
+import TableOfContents from './TableOfContents.js'
+
+export default {
+  components: {
+    EditorContent,
+  },
+
+  data() {
+    return {
+      editor: null,
+    }
+  },
+
+  mounted() {
+    this.editor = new Editor({
+      extensions: [
+        ...defaultExtensions(),
+        TableOfContents,
+      ],
+      content: `
+        <toc></toc>
+        <h2>heading</h2>
+        <p>paragraph</p>
+        <h3>heading</h3>
+        <p>paragraph</p>
+        <h3>heading</h3>
+        <p>paragraph</p>
+        <h2>heading</h2>
+        <p>paragraph</p>
+        <h3>heading</h3>
+        <p>paragraph</p>
+      `,
+    })
+  },
+
+  beforeDestroy() {
+    this.editor.destroy()
+  },
+}
+</script>