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.

05-es6-plus/07-arrow-this/README.md

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+# 练习 7：箭头函数里的 this
+
+## 目标
+
+理解箭头函数不会创建自己的 `this`。
+
+## 你要练什么
+
+- 箭头函数
+- `this`
+- 定时器回调
+
+## 任务
+
+- 在对象方法里用箭头函数处理 `setTimeout`
+- 让延迟输出仍然拿到当前对象的名称
+
+## 文件
+
+- [starter.html](/Users/lijiaqing/home/wwwroot/front-end-example/05-es6-plus/07-arrow-this/starter.html)
+- [starter.js](/Users/lijiaqing/home/wwwroot/front-end-example/05-es6-plus/07-arrow-this/starter.js)
+- [answer.html](/Users/lijiaqing/home/wwwroot/front-end-example/05-es6-plus/07-arrow-this/answer.html)
+- [answer.js](/Users/lijiaqing/home/wwwroot/front-end-example/05-es6-plus/07-arrow-this/answer.js)