Better coding style

web/dart/navbar.dart

@@ -9,9 +9,7 @@ String getPageTitle() {
 
 Element makeIcon(List<String> classes, [String id]) {
   final icon = Element.tag('i')..classes.addAll(classes);
-  if (id != null) {
-    icon.attributes['id'] = id;
-  }
+  icon.attributes['id'] = id ?? '';
   return icon;
 }
 
@@ -33,7 +31,7 @@ Future<Element> makePages() async {
       ..attributes['href'] = 'javascript:void(0)'
       ..append(makeIcon(['fas', 'fa-flag'])))
     ..classes.addAll(['nav-item', 'has-dropdown'])
-    ..insertAdjacentElement('beforeEnd', pages);
+    ..append(pages);
 }
 
 Element makeShareLink(Element icon, String url) {