✨ feat: add section headings (#210)

public/templates/engines_tab.html

@@ -1,4 +1,5 @@
 <div class="engines tab">
+    <h1>Engines</h1>
     <h3>select search engines</h3>
     <p class="description">
         Select the search engines from the list of engines that you want results

public/templates/user_interface_tab.html

@@ -1,4 +1,5 @@
 <div class="user_interface tab">
+    <h1>User Interface</h1>
     <h3>select theme</h3>
     <p class="description">
         Select the theme from the available themes to be used in user interface