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/04-modules-basic/answer.js

@@ -0,0 +1,4 @@
+import { courses, formatCourse } from "./course-data.js";
+
+const lines = courses.map((course) => formatCourse(course));
+document.getElementById("output").textContent = lines.join("\n");