Make it possible to disable the comments section entirely without having to muck with theme files.

.themes/classic/source/_includes/comments.html

@@ -1,3 +1,4 @@
+{% if site.use_comments %}
 <section>
   <h1>Comments</h1>
   {% include custom/comments.html %}
@@ -5,3 +6,4 @@
     <div id="disqus_thread" aria-live="polite">{% include post/disqus_thread.html %}</div>
   {% endif %}
 </section>
+{% endif %}

.themes/classic/source/_includes/custom/comments.html

@@ -1,3 +1,5 @@
 {% comment %}
 To use a custom comment system, add the javascript to custom/after_footer.html then add the container for your comments here.
+
+Be sure to set "use_comments: true" in site.yml or the comments section will not be displayed!
 {% endcomment %}

_config/defaults/disqus.yml

@@ -3,6 +3,8 @@
 #   Disqus Comments Configuration   #
 # --------------------------------- #
 
+# In order to use Disqus you must both set the short name here, AND set
+# "use_comments: true" in site.yml.
 disqus_short_name:
 disqus_show_comment_count: false
 disqus_developer: 0