Provide an OpenAPI specification for the API

[th0mk]

Use-Case Description

When the API releases, it would be nice to have an OpenAPI specification available. This allows many useful things and makes implementation much easier. For example, people would be able to automatically generate client libraries using autorest

There are tools available to generate this specification automatically, but I'm not that familiar with rust so not sure if this is an easy thing to do.

[aramperes]

Sadly there's no production-ready option to generate OpenAPI specifications automatically with our stack (actix-web). paperclip seems promising but it's a bit early to use in production.

Of course it would still be possible to write one manually, at least when v1beta is stabilized to v1 and there won't be any more major changes.