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/10-final-dashboard/starter.js

@@ -0,0 +1,22 @@
+const lessons = [
+  { title: "获取元素", done: false },
+  { title: "修改 DOM", done: true },
+];
+
+function fakeLoadExtraLessons() {
+  return new Promise(function (resolve) {
+    setTimeout(function () {
+      resolve([
+        { title: "事件委托", done: false },
+        { title: "异步渲染", done: false },
+      ]);
+    }, 900);
+  });
+}
+
+// 任务：
+// 1. 获取页面里的关键元素
+// 2. 写一个 renderLessons 函数，把 lessons 渲染到列表
+// 3. 点击列表项时切换 done 状态
+// 4. 提交表单时阻止默认提交，并新增课程
+// 5. 点击加载按钮时显示加载状态，并把异步返回的课程追加到列表