chore: use openapi doc from Flipt repo; add OFREP docs

[markphelps]

Re: flipt-io/flipt#3357

@erka I noticed that enums are now returned as integer types in the generated OpenAPI spec. I wonder if there is a way we can override that to denote the string values?

[erka]

@markphelps probably enum_type=string opt for google-gnostic-openapi could help with it in buf.gen.yaml. Does it solve this problem?

[erka]

nice!

The drawback is that the openapi.yaml could have unreleased feature in main. I think that will be a rare event.

[markphelps]

@markphelps probably enum_type=string opt for google-gnostic-openapi could help with it in buf.gen.yaml. Does it solve this problem?

I will try it. Good shout

[markphelps]

nice!

The drawback is that the openapi.yaml could have unreleased feature in main. I think that will be a rare event.

Yeh it won't actually show on the docs until we add the mdx files and add it to mint.json so shouldn't be an issue