docs: remove stray comma

Author: Kijewski

util/gh-pages/index_template.html

@@ -104,7 +104,7 @@ <h1>Clippy Lints</h1> {# #}
                                 <li role="separator" class="divider"></li> {# #}
                             </ul> {# #}
                         </div> {# #}
-                        <div class="btn-group", id="lint-applicabilities" tabindex="-1"> {# #}
+                        <div class="btn-group" id="lint-applicabilities" tabindex="-1"> {# #}
                             <button type="button" class="btn btn-default dropdown-toggle"> {# #}
                                 Applicability {#+ #}
                                 <span class="badge">4</span> {#+ #}