Hiding custom search engine UI in settings page

Due to content scripts being unregistered on-update

pages/settings/index.html

@@ -212,7 +212,11 @@
             </label>
           </div>
         </fieldset>
-        <fieldset id="customSearchEngines">
+        <!--
+          Custom search engines are currently disabled 
+          due to content scripts being unregistered on-update.
+        -->
+        <!-- <fieldset id="customSearchEngines">
           <legend>
             <span aria-hidden="true">🔍</span> Custom search engines
           </legend>
@@ -227,7 +231,7 @@
               <button id="addCustomSearchEngine">Add</button>
             </div>
           </div>
-        </fieldset>
+        </fieldset> -->
         <h2>Individual wiki settings</h2>
         <fieldset id="legend">
           <legend>