Replace old Disqus script with Universal Embed Code (#1179)

* update embeddable disqus javascript

* Update disqus.html

_includes/comments-providers/disqus.html

@@ -1,22 +1,16 @@
 {% if site.comments.disqus.shortname %}
-  <script type="text/javascript">
-  	/* * * CONFIGURATION VARIABLES: EDIT BEFORE PASTING INTO YOUR WEBPAGE * * */
-  	var disqus_shortname = '{{ site.comments.disqus.shortname }}';
-
-  	/* * * DON'T EDIT BELOW THIS LINE * * */
-  	(function() {
-  		var dsq = document.createElement('script'); dsq.type = 'text/javascript'; dsq.async = true;
-  		dsq.src = '//' + disqus_shortname + '.disqus.com/embed.js';
-  		(document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(dsq);
-  	})();
-
-  	/* * * DON'T EDIT BELOW THIS LINE * * */
-  	(function () {
-  		var s = document.createElement('script'); s.async = true;
-  		s.type = 'text/javascript';
-  		s.src = '//' + disqus_shortname + '.disqus.com/count.js';
-  		(document.getElementsByTagName('HEAD')[0] || document.getElementsByTagName('BODY')[0]).appendChild(s);
-  	}());
+  <div id="disqus_thread"></div>
+  <script>
+    var disqus_config = function () {
+      this.page.url = "{{ page.url | absolute_url }}";  // Replace PAGE_URL with your page's canonical URL variable
+      this.page.identifier = "{{ page.id }}"; // Replace PAGE_IDENTIFIER with your page's unique identifier variable
+    };
+    (function() { // DON'T EDIT BELOW THIS LINE
+      var d = document, s = d.createElement('script');
+      s.src = 'https://{{ site.comments.disqus.shortname }}.disqus.com/embed.js';
+      s.setAttribute('data-timestamp', +new Date());
+      (d.head || d.body).appendChild(s);
+    })();
   </script>
-  <noscript>Please enable JavaScript to view the <a href="http://disqus.com/?ref_noscript">comments powered by Disqus.</a></noscript>
-{% endif %}
+<noscript>Please enable JavaScript to view the <a href="https://disqus.com/?ref_noscript">comments powered by Disqus.</a></noscript>
+{% endif %}