disabled

www/index.html

                   <th>1. Tag Name</th>
                   <td>
                     <select class="custom-select autodoc_tag_list">
-                      <option>Choose tag to edit</option>
+                      <option disabled>Choose tag to edit</option>
                       <option value="">New tag...</option>
                     </select>
                     <input type="hidden" class="autodoc_tag_id" value="">