website(menu): Update menu styles.

Author: jaywcjlove

website/src/component/Header/index.module.less

@@ -31,7 +31,7 @@
     margin-left: 6px;
   }
   :global(.active), a:hover {
-    background: #f0f1f2;
+    background: #00000017;
     color: #0366d6;
   }
 }