message: docs: fix depth prop
diff: <nav>
  <p class="font-bold text-xs uppercase text-gray">On this page</p>
  <ul class="mt-4 space-y-1 text-sm">
  - <li v-for="heading in headings" :key="heading.id" :class="{ 'ml-4': heading.level === 3 }">
  + <li v-for="heading in headings" :key="heading.id" :class="{ 'ml-4': heading.depth === 3 }">
  <a class="inline-block py-1" :href="`#${heading.id}`">{{ heading.text }}</a>
  </li>
  </ul>
  