fix typos

index.md

@@ -21,7 +21,7 @@ nav_order: 1
 >点击加入官方QQ群: [735728797](https://jq.qq.com/?_wv=1027&k=2OYDP4Tk)  
 >[正(繁)體字版官方網站](https://zhuyuhao.com/yuhaoim)  
 >[稳定版v1.4.3下载](https://github.com/forFudan/yuhao/releases/tag/v1.4.3) ·
->[内测版v2.0.0-alpha.1下载（四重注解）](https://github.com/forFudan/yuhao/releases/tag/v2.0.0-alpha.1)  
+>[内测版v2.0.0-alpha.2下载（四重注解）](https://github.com/forFudan/yuhao/releases/tag/v2.0.0-alpha.2)  
 >[快速指南](./docs/cookbook/cookbook) ·
 >[详细教程](./docs/learn) ·
 >[在线练习](./docs/practice) ·