Load disqus on scroll

a demo.md

https://jsfiddle.net/retrolione/hn57eqd7/14/

comments.html

<div class="comments">
  <div id="disqus_thread"></div>
</div>

<script type="text/javascript" src="comments.js"></script>

comments.js

// Disqus is a giant turd when loading, even without any comments it slows your site down.
// This script loads disqus when you scroll to a certain div aka comments
<script type="text/javascript" src="https://cdn.jsdelivr.net/jquery.waypoints/2.0.5/waypoints.js"></script>
<script type="text/javascript">
var loaded = 0; // make sure its only loaded once
var disqus_shortname = "whatever"; // change this to your shortname 
$('.comments').waypoint(function() {
    if (loaded == 0) {
           $.ajax({
               type: "GET",
               url: "http://" + disqus_shortname + ".disqus.com/embed.js",
               dataType: "script",
               cache: true
           });
        	loaded = 1;
    }
});
</script>