input: |
  >! TIP: test
  >
  > > >! NOTE: cool
  > > > cool
  > >
  > > interesting
  >
  > >? NOTE: hmm
output: |-
  <details class="tip" open="open">
    <summary>
      Tip
    </summary>
    <p>
      test
    </p>
    <blockquote>
      <details class="note" open="open">
        <summary>
          Note
        </summary>
        <p>
          cool
  cool
        </p>
      </details>
      <p>
        interesting
      </p>
    </blockquote>
    <details class="note">
      <summary>
        Note
      </summary>
      <p>
        hmm
      </p>
    </details>
  </details>
