Merge pull request #3320 from overleaf/hb-spellcheck-visibility-on-current-line

Add z-index to spellcheck highlight to make it always visible in some themes

GitOrigin-RevId: 5e29ec5ddb6dd40d908e6c044f529edbcf0dd615

services/web/frontend/stylesheets/app/editor.less

@@ -256,6 +256,7 @@ Ace
     height: 100%;
   }
   .spelling-highlight {
+    z-index: 3;
     position: absolute;
     background-image: url(/img/spellcheck-underline.png);
     @media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {