docs: consolidate API docs and update readme files (#2944)

* docs: consolidate API docs and update readme files

Moves api docs into `/docs` folder similarly to how js-libp2p has organised
their docs.

Tries to trim readmes down a bit to make them more digestible and
adds links to futher information on different topics.

Also reinstates dependency statuses.

Co-authored-by: Hugo Dias <hugomrdias@gmail.com>