Docs for 2.1

[wileyj]

Bump for 2.1 docs detaliling any new routes/schemas

i.e.: /stacker/:principal -> https://github.com/hirosystems/stacks-blockchain-api/blob/stacks-2.1/src/api/routes/pox2.ts#L59

[sabbyanandan]

Thanks for reporting, @wileyj. We will get this updated.