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/07-timers-and-async-order/answer.js

@@ -0,0 +1,20 @@
+const runButton = document.getElementById("run-btn");
+const logList = document.getElementById("log-list");
+
+function appendLog(text) {
+  const item = document.createElement("li");
+  item.textContent = text;
+  logList.appendChild(item);
+}
+
+runButton.addEventListener("click", function () {
+  logList.innerHTML = "";
+
+  appendLog("开始执行");
+
+  setTimeout(function () {
+    appendLog("异步回调完成");
+  }, 600);
+
+  appendLog("同步代码结束");
+});