feat: Improve public api

[WcaleNieWolny]

Recently, there has been an proposed rename to some database fields. This change would have affected the public API if it was not caught. I DO NOT think that we should keep the same API structure forever nor do I think that the current way of documenting our api is any good.

I propose that we

A) Start versioning the public API
The endpoint would look something like: https://api.capgo.app/v1/channel

B) Set a clear API deprecation policy. We promise to inform of any changes made to the API (promise to inform of a new API version release) and we promise to keep the old api version for 6 months. After that we will deprecate the api. It will return a 410 gone

C) Improve the documentation by using openAPI and swagger