post_show.html.erb

 <h1><%= markdown_to_html @post.title %></h1>

 <div class="row">

   <div class="col-md-8">

    <small>
      <%= image_tag(@post.user.avatar.tiny.url) if @post.user.avatar? %>
      submitted <%= time_ago_in_words(@post.created_at) %> ago by
      <%= @post.user.name %>
    </small>
    <p><%= markdown_to_html @post.body %></p>

    <% @comments.each do |comment| %>
      <%= comment.body %></p>
    <% end %>
    <%= render partial: 'comments/form', locals: {post: @post, comment: @comment} %>
   </div>

   <div class="col-md-4">
     <% if policy(@post).edit? %>
       <%= link_to "Edit", edit_topic_post_path(@topic,@post), class: 'btn btn-success' %>
     <% end %>
   </div>
 </div>