I don't want to crash this getdoks post (so you should check it out) but I searched far and wide across different docs setups and I'm SO happy with Starlight from the Astro folks.[1]
Supports Markdown, Markdoc (powers Stripe docs & is what we're using), MDX, and of course HTML. Since it's built on Astro, it's super easy to extend with React, Vue, Svelte, Solid, or Qwik for interactive demos, code sandboxes, or other more complex features.