Make a microsite with organized docs

[armanbilge]

Emphasis on organized, as we continue adding clouds that each need their own docs it's going to get complicated. Not entirely sure if we'll be able to use mdoc or will need mdoc.js for the Scala.js-only modules. It's a bit of a strange situation, since mdoc.js is intended for interactive browser-based Scala.js snippets, but we'll be compiling code targeting Node.js that won't run in the browser. So not quite sure if/how that would work.

Regarding site generator, I'm amenable to Laika, which I had a pleasant experience using for http4s-dom. Also the new docs generation capabilities in Scaladoc 3 seem interesting, see scalameta/mdoc#588 (comment).