markdown optimization, few other changes

app/views/comments/_comment.html.erb

@@ -6,7 +6,7 @@
   </div>
   <div class="items">
     <div class="item content">
-      <%= Sanitize.clean(render_mini_md(c.content.gsub(/([\r\n]+\s*?){3,}/, "\n\n")), Sanitize::Config::BASIC).html_safe %>
+      <%= render_mini_md(c.content).html_safe %>
     </div>
   </div>
 </div>

app/views/comments/_new.html.erb

@@ -1,7 +1,7 @@
 <% if current_user %>
   <h3>New comment</h3>
   <%= simple_form_for [@post, @comment] do |f| %>
-    <p>> quote | _underline_ | *italic* | **bold** | `code` | [link](https://example.com)
+    <p><blockquote>&gt; quote</blockquote> | _underline_ | <i>*italic*</i> | <b>**bold**</b> | <code>`code`</code> | <mark>==mark==</mark> | <a>[link](https://example.com)</a>
     <%= f.input :content, :label => false, :as => "text", :placeholder => "Comment", input_html: {class: "comment"} %>
     <%= f.submit class: "btn blue" %>
   <% end %>