Add commento.io support (#564)

Signed-off-by: hossainemruz <hossainemruz@gmail.com>

layouts/partials/comments/valine.html

@@ -0,0 +1,18 @@
+{{ with .valine }}
+<div id="vcomments"></div>
+<script src="//cdn1.lncld.net/static/js/3.0.4/av-min.js"></script>
+<script src="//unpkg.com/valine/dist/Valine.min.js"></script>
+<script type="text/javascript">
+  new Valine({
+    el: "#vcomments",
+    appId: "{{ .appId }}",
+    appKey: "{{ .appKey }}",
+    avatar: "{{ .avatar }}",
+    placeholder: "{{ .placeholder }}",
+    visitor: "{{ .visitor }}",
+    lang: "{{ .lang }}",
+    recordIP: "{{ .recordIP }}",
+    enableQQ: "{{ .enableQQ }}",
+  });
+</script>
+{{ end }}