JSFiddle - React, Tailwind, and code Playground

HTML

<ol class="level0">
  <li>This Website
    <ol>
      <li>This website</li>
      <li>etc etc</li>
    </ol>
  </li>
  <li>...
    <ol>
      <li>...</li>
      <li>...</li>
    </ol>
  </li>
</ol>

CSS

ol {
  counter-reset: section;
  list-style-type: none;
}

ol.level0 > li:before {
  counter-increment: section;
  content: counters(section, ".") ".0 ";
}

li:before {
  counter-increment: section;
  content: counters(section, ".") " ";
}