<ol class="tree">
      <li>
        <label>folder0</label> <input type="checkbox" checked />
        <ol>
  <li class="file"><a href="folder0/0">0</a></li>
        </ol>
      </li>
      <li>
        <label>folder1</label> <input type="checkbox" checked />
        <ol>
  <li class="file"><a href="folder1/1">1</a></li>
</ol>