input: |
  > [!Warning]
  a

  <!-- -->

  > [!Warning]
  >>
output: |-
  <div class="admonition warning">
    <p class="admonition-title">
      Warning
    </p>
    <p>
      a
    </p>
  </div>
  <!-- -->
  <div class="admonition warning">
    <p class="admonition-title">
      Warning
    </p>
    <blockquote>
    </blockquote>
  </div>
