added a todo comment

packages/app/src/styles/theme/_apply-colors.scss

@@ -542,6 +542,7 @@ body.pathname-sidebar {
   }
 
   .grw-pagetree-item {
+    // TODO: apply variable to　these bg-color  for each theme by 83526
     &:hover {
       background: #e0e6f7;
     }