Update README.md

Author: xaoxuu

README.md

@@ -32,7 +32,7 @@
 ```yaml
 title: xaoxuu
 url: https://xaoxuu.com
-avatar: https://xaoxuu.com/assets/xaoxuu/2021/09/24/2f74810ceb3d3.png
+avatar: https://xaoxuu.com/assets/xaoxuu/avatar/rect-256@2x.png
 screenshot: https://xaoxuu.com/assets/xaoxuu/2022/10/23/63542895cfd29.png
 description: For all time, always.
 ```