friendenstein/templates/toc.html

<div class="toc">
<h2>Table of contents</h2>
<ul>
  {% for h1 in page.toc %}
  <li>
    <a href="{{ h1.permalink | safe }}">{{ h1.title }}</a>
    {% if h1.children %}
    <ul>
      {% for h2 in h1.children %}
      <li>
        <a href="{{ h2.permalink | safe }}">{{ h2.title }}</a>
        <ul>
          {% for h3 in h2.children %}
          <li>
            <a href="{{ h3.permalink | safe }}">{{ h3.title }}</a>
          </li>
          {% endfor %}
        </ul>
      </li>
      {% endfor %}
    </ul>
    {% endif %}
  </li>
  {% endfor %}
</ul>
</div>