add disqus.js

layout/includes/comments/disqusjs.pug

@@ -0,0 +1,16 @@
+if theme.disqusjs && theme.disqusjs.enable
+  #disqus_thread
+  link(href=('https://cdn.jsdelivr.net/npm/disqusjs@1.2/dist/disqusjs.css') rel='stylesheet')
+  script(src=('https://cdn.jsdelivr.net/npm/disqusjs@1.2/dist/disqus.js'))
+  script.
+    var dsqjs = new DisqusJS({
+      shortname: '!{theme.disqusjs.shortname}',
+      siteName: "!{theme.disqusjs.siteName}",
+      identifier: '!{ page.path }',
+      url: '!{ page.permalink }',
+      title: '!{ page.title }',
+      api: '!{theme.disqusjs.api}',
+      apikey: '!{theme.disqusjs.apikey}',
+      admin: '',
+      adminLabel: ''
+    });