feat: add TypeScript lessons and learning panel

- Introduced a new script to check TypeScript lesson files for errors.
- Created a main TypeScript file to render lessons and their details.
- Added lesson definitions with starter and answer codes.
- Implemented a user interface for navigating and running lessons.
- Styled the application with CSS for a better user experience.
- Updated README to reflect the new TypeScript section and usage instructions.

04-dom-events-async/03-create-and-remove/README.md

@@ -0,0 +1,24 @@
+# 练习 3：创建和删除节点
+
+## 目标
+
+学会动态新增和删除页面节点。
+
+## 你要练什么
+
+- `createElement`
+- `appendChild`
+- `remove`
+- 事件绑定
+
+## 任务
+
+- 点击“新增任务”时往列表里加一个新项
+- 点击“删除最后一项”时删除最后一个列表项
+
+## 文件
+
+- [starter.html](/Users/lijiaqing/home/wwwroot/front-end-example/04-dom-events-async/03-create-and-remove/starter.html)
+- [starter.js](/Users/lijiaqing/home/wwwroot/front-end-example/04-dom-events-async/03-create-and-remove/starter.js)
+- [answer.html](/Users/lijiaqing/home/wwwroot/front-end-example/04-dom-events-async/03-create-and-remove/answer.html)
+- [answer.js](/Users/lijiaqing/home/wwwroot/front-end-example/04-dom-events-async/03-create-and-remove/answer.js)