feat: rename project to TTTK

- Update package name and CLI binary to 'tttk'
- Revise documentation to reflect new name
- Add default serve behavior when no subcommand is given
- Add directory existence check in serve command
- Refactor inline comments to Chinese

src/cli/commands/compile.ts

@@ -1,14 +1,14 @@
-import type { CompileCommandHandler } from '../types.js';
+import type { CompileCommandHandler } from "../types.js";
 
 export const compileCommand: CompileCommandHandler = async (dir, options) => {
-  console.log(`开始编译...`);
-  console.log(`目录：${dir}`);
+  console.log("开始编译...");
+  console.log(`源目录：${dir}`);
   console.log(`输出目录：${options.output}`);
-  
+
   // TODO: 实现编译逻辑
   // 1. 扫描目录下的所有 .md 文件
   // 2. 解析 markdown 并生成路由
   // 3. 打包为带 hash 路由的单个 HTML 入口
-  
-  console.log('编译完成！');
+
+  console.log("编译完成！");
 };