JSFiddle - React, Tailwind, and code Playground

HTML

<ol>
 <li>Entry
 <li>Entry
 <li>Entry with subentries
  <ol>
      <li>Entry
      <li>Entry
      <li>Entry
      <li>Entry
  </ol>
 <li>Entry
 <li>Entry
 <li>Entry with subentries
  <ol>
      <li>Entry
      <li>Entry
      <li>Entry
      <li>Entry
  </ol>
</ol>

CSS

ol {
  counter-reset: section;                /* Creates a new instance of the
                                            section counter with each ol
                                            element */
  list-style-type: none;
}
li:before {
  counter-increment: section;            /* Increments only this instance
                                            of the section counter */
  content: counters(section, ".") " ";   /* Adds the value of all instances
                                            of the section counter separated
                                            by a ".". */
}