fix task list example

docs/src/demos/Examples/TodoApp/index.vue

@@ -18,7 +18,7 @@ const CustomDocument = Document.extend({
 })
 
 const CustomTaskItem = TaskItem.extend({
-  content: 'paragraph',
+  content: 'inline*',
 })
 
 export default {

packages/extension-task-item/src/index.ts

@@ -79,6 +79,7 @@ const TaskItem = Node.create({
       const content = document.createElement('div')
 
       checkbox.type = 'checkbox'
+      checkbox.contentEditable = 'false'
       checkbox.addEventListener('change', event => {
         const { checked } = event.target as any