toc.rb

{% if site.toc %}
  <div class="container">  
    <div class="contents">
      <article class="markdown-body">
        {{ page.content }}
      </article>
    </div>   
    <div class="table-of-contents">
      <h2>Contents</h2>
      {% include toc.html html=content %}
    </div>
  </div>
{% else %}
  <article class="markdown-body">
    {{ page.content }}
  </article>
{% endif %}