Documentation: Integrate odoc to generate documentation

[bryphe]

odoc is a great OCaml-community-supported project for generating documentation - and it even integrates with esy. It'd be awesome if we could use it to generate some initial documentation.

I imagine we'll need to do a better job of documenting in the files (using the proper code-block comments to get good descriptions in the documentations) - it'd be helpful to know what we need to do there to get high-quality docs.

[ulrikstrid]

cc @ostera

[Akin909]

@samatar26 (@bryphe, @samatar26 is a friend who is interested in helping out, he's a JS developer, new to reason), this might be a good issue for you to start with if you want to help out, might need to have a look at the docs for odoc and see how to integrate it here then maybe find some comments and change them to the right ones (its in the docs) and see if you can output some docs

[wokalski]

We've been also trying to research this for Brisk. It'd be great to use the same infra.

[ulrikstrid]

Might want to have a look here on how to generate the docs in CI: https://github.com/esy-ocaml/hello-reason/blob/master/.ci/utils/create-docs.yml

[ulrikstrid]

The infra is actually done in #251, when we land #272 with some actual docs I think this can be closed