Add support for Commento (spf13#74)

Add support for Commento

README.md

@@ -73,6 +73,9 @@ __`Hyde-hyde`__ essentially inherits most of Hyde's [options](https://github.com
   * `UtterancesIssueTerm = "pathname"` Method for Utterances to match issue's to posts (pathname, url, title, og:title)
   * `UtterancesTheme = "github-light"` Theme for Utterances (github-light, github-dark)
 
+* `Commento = true`: to use [Commento](https://commento.io/) instead of the built-in [Disqus](https://disqus.com). This option should be used exclusively with `disqusShortname = "disqus-shortname"`.
+  * `CommentoHost = "your-commento-instance"` [Self-hosted Commento](https://docs.commento.io/installation/self-hosting/) instance. This is not required if you're a [Commento.io](https://commento.io) user.
+
 * `[params.social]`: in this section, you can set many social identities such as Twitter, Facebook, Github, Bitbucket, Gitlab, Instagram, LinkedIn, StackOverflow, Medium, Xing, Keybase.
 
   ```toml

layouts/partials/page-single/comment/commento.html

@@ -0,0 +1,25 @@
+<div id="commento"></div>
+<script type="text/javascript">
+    /* 
+      Check and don't inject Commento on localhost/127.0.0.1, however, it does not
+      work for customised local domains, e.g. example.test, example.dev
+    */
+    (function () {
+    if (location.hostname === "localhost" ||
+      location.hostname === "127.0.0.1" ||
+      location.hostname === "") {
+      return;
+    }
+    var cmt = document.createElement('script');
+    cmt.type = 'text/javascript';
+    cmt.async = true;
+    var commento_host = '{{ with .Site.Params.CommentoHost }}{{ . }}{{else}}https://cdn.commento.io{{ end }}';
+    cmt.src = commento_host + '/js/commento.js';
+    (document.getElementsByTagName('head')[0] || 
+      document.getElementsByTagName('body')[0]).appendChild(cmt);
+  })();
+</script>
+
+<noscript>
+  Please enable JavaScript to load the comments.
+</noscript>

layouts/partials/page-single/post-comment.html

@@ -5,5 +5,7 @@
         {{ partial "page-single/comment/graphcomment.html" . }}
     {{ else if .Site.Params.UtterancesRepo }}
         {{ partial "page-single/comment/utterances.html" . }}
+    {{ else if .Site.Params.Commento }}
+        {{ partial "page-single/comment/commento.html" . }}
     {{ end }}
 {{ end }}