'Article' to 'DiscussionForumPosting' schema type

topic => https://meta.discourse.org/t/invalid-article-schema/57037
Replacing '[Article](https://schema.org/Article)' schema type with '[DiscussionForumPosting](https://schema.org/DiscussionForumPosting)'

app/views/topics/show.html.erb

@@ -42,7 +42,7 @@
 <%- if include_crawler_content? %>
 
 <% @topic_view.posts.each do |post| %>
-  <div itemscope itemtype='http://schema.org/Article'>
+  <div itemscope itemtype='http://schema.org/DiscussionForumPosting'>
     <% if (u = post.user) %>
       <div class='creator'>
         <span>