website/templates/blog/_toc.html

<aside class="toc">
  <h2>Table of Contents</h2>
  {% if page.toc %}
  <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>
          {% if h2.children %}
          <ul>
            {% for h3 in h2.children %}
            <li>
              <a href="{{ h3.permalink | safe }}">{{ h3.title }}</a>
              {% if h3.children %}
              <ul>
                {% for h4 in h3.children %}
                <li>
                  <a href="{{ h4.permalink | safe }}">{{ h4.title }}</a>

                  {% if h4.children %}
                  <ul>
                    {% for h5 in h4.children %}
                    <li>
                      <a href="{{ h5.permalink | safe }}">{{ h5.title }}</a>

                      {% if h5.children %}
                      <ul>
                        {% for h6 in h5.children %}
                        <li>
                          <a href="{{ h6.permalink | safe }}">{{ h6.title }}</a>
                        </li>
                        {% endfor %}
                      </ul>
                      {% endif %}
                    </li>
                    {% endfor %}
                  </ul>
                  {% endif %}
                </li>
                {% endfor %}
              </ul>
              {% endif %}
            </li>
            {% endfor %}
          </ul>
          {% endif %}
        </li>
        {% endfor %}
      </ul>
      {% endif %}
    </li>
    {% endfor %}
  </ul>
  {% endif %}
</aside>