fix: added _includes

_includes/comments/disqus.html

@@ -0,0 +1,49 @@
+<!-- The Disqus lazy loading. -->
+<div id="disqus_thread" class="pt-2 pb-2">
+  <p class="text-center text-muted small">Comments powered by <a href="https://disqus.com/">Disqus</a>.</p>
+</div>
+
+<script type="text/javascript">
+  var disqus_config = function () {
+    this.page.url = '{{ page.url | absolute_url }}';
+    this.page.identifier = '{{ page.url }}';
+  };
+
+  /* Lazy loading */
+  var disqus_observer = new IntersectionObserver(
+    function (entries) {
+      if (entries[0].isIntersecting) {
+        (function () {
+          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);
+        })();
+
+        disqus_observer.disconnect();
+      }
+    },
+    { threshold: [0] }
+  );
+
+  disqus_observer.observe(document.querySelector('#disqus_thread'));
+
+  /* Auto switch theme */
+  function reloadDisqus() {
+    if (event.source === window && event.data && event.data.direction === ModeToggle.ID) {
+      /* Disqus hasn't been loaded */
+      if (typeof DISQUS === 'undefined') {
+        return;
+      }
+
+      if (document.readyState == 'complete') {
+        DISQUS.reset({ reload: true, config: disqus_config });
+      }
+    }
+  }
+
+  if (document.querySelector('.mode-toggle')) {
+    window.addEventListener('message', reloadDisqus);
+  }
+</script>