app/views/shared/_challenge_description.erb
<p><%= show_challenge.description %></p>
<h5>Start file</h5>
<pre class="prettyprint"><%= show_challenge.input %></pre>
<h5>End file</h5>
<pre class="prettyprint"><%= show_challenge.output %></pre>
<h4><a href="#" onclick="toggle('diff'); return false;">View Diff</a></h4>
<pre class="prettyprint" id="diff"><%= show_challenge.diff %></pre>