[Docs] Dockerize flyteidl docs generation

[MorpheusXAUT]

Description

Whilst most of the docs auto-generated for flyteidl are already using some docker image to build, one step still requires a local installation of protoc, which is not managed by the repo/boilerplate setup. Furthermore, the protoc version required/used is not documented anywhere (except when checking the GitHub actions workflow to see which one is auto-installed).

Generating all docs using Docker images would allow for an easier initial setup for flyteidl contributors as well as more consistent docs generation (no longer dependent on dependencies installed on local machine).

Are you sure this issue hasn't been raised already?

• Yes

Have you read the Code of Conduct?

• Yes