Add comments to JavaScript and some restructuring

app/templates/main/_manual_modal.html.j2

@@ -1,7 +1,7 @@
 <div id="manual-modal" class="modal no-autoinit">
   <div class="modal-content">
     <h2>Manual</h2>
-    <ul class="tabs no-autoinit" id="manual-modal-table-of-contents">
+    <ul class="tabs" id="manual-modal-toc">
       <li class="tab"><a href="#manual-modal-introduction">Introduction</a></li>
       <li class="tab"><a href="#manual-modal-registration-and-log-in">Registration and Log in</a></li>
       <li class="tab"><a href="#manual-modal-dashboard">Dashboard</a></li>