add mark

src/demos/HandleExtensions/index.vue

@@ -19,6 +19,7 @@ import Document from '@tiptap/extension-document'
 import Paragraph from '@tiptap/extension-paragraph'
 import Text from '@tiptap/extension-text'
 import History from '@tiptap/extension-history'
+import Bold from '@tiptap/extension-bold'
 
 export default {
   components: {
@@ -39,6 +40,7 @@ export default {
         new Paragraph(),
         new Text(),
         new History(),
+        new Bold(),
       ],
     })
   },