Add a placeholder for blog comments (#464)

Author: stefanv

layouts/partials/posts/comments.html

@@ -14,6 +14,7 @@ <h5 class="subtitle">{{ .Params.Subtitle }}</h5>
       </div>
       {{ end }}
       {{ .Content }}
+      {{ partial "posts/comments.html" .}}
     </div>
   </div>
   {{ partial "shortcuts.html" . }}