Dockerize codegen CLI

[beeme1mr]

Create a Dockerfile to build a Dockerized codegen cli. The resulting image should be as lightweight as possible. The flagd Dockerfile may be a good starting point.

https://github.com/open-feature/flagd/blob/main/flagd/build.Dockerfile

[thomaspoignant]

If you create the docker container from goreleaser it could be even lighter, since goreleaser is building the binary on their side.
Here an example used for GO Feature Flag.

[beeme1mr]

#37