papercss/docs/layouts/partials/nav/sidebar.html

<div class='sm-12 md-4 col sidebar'>
    {{ range .Site.Sections }}
    <div class='paper'>
      <h3 class='sidebar-title' style='text-align:center'>
        <a href='/docs'>Documentation</a>
      </h3>
      <div class='row'>
        {{ range .Sections }}
        <div class='collapsible full-width'>
          <input id='collapsible-{{ .Title | urlize }}' type='radio' name='collapsible'>
          <label for="collapsible-{{ .Title | urlize }}">{{ .Title }}</label>
          <div class="collapsible-body">
            <ul>
            {{ range .Pages }}
              <li>
                <a href='{{ .Permalink | relURL }}'>{{ .Title }}</a>
              </li>
            {{ end }}
            </ul>
          </div>
        </div>
        {{ end }}
      </div>
    </div>
    {{ end }}
    <div class='paper'>
      <div class="row flex-center">
        <p>Made with 💛 by <a href="https://vlaservich.com" target="_blank">Rhyne</a> and some <a href="https://github.com/rhyneav/papercss/graphs/contributors">fantastic contributors</a>!</p>
      </div>
    </div>
</div>