small refactor and cleanup to comments system

_includes/staticman-comments.html

@@ -1,4 +1,5 @@
 {% if site.staticman.repository and site.staticman.branch %}
+<div class="staticman-comments">
   <div class="page__comments">
     <!-- Start static comments -->
     <div class="js-comments">
@@ -78,4 +79,5 @@
     }
   </script>
   <script src="{{ "/js/staticman.js" | relative_url }}"></script>
+</div>
 {% endif %}