Fix typos in some files

GUI/settings.html

@@ -183,7 +183,7 @@
                         <input name="opacity" type="range" class="form-range" min="0" max="1" step="0.05"
                             value="{{ data.opacity }}" data-toggle="tooltip" data-original-title="{{ data.opacity }}">
                     </div>
-                    <span class="form-text text-muted">Sets the opacity of the comments when overlayed over the
+                    <span class="form-text text-muted">Sets the opacity of the comments when overlaid over the
                         background.</span>
                 </div>
             </div>