[REQ] Support multi-module repos for gomod generator

[cpuguy83]

What kind of request is this?

New feature

What is your request or suggestion?

Currently the gomod generator only supports generating gomods for a single module. In order to have multiple modules one would have to define this as multiple sources.

I propose we add a field to the gomod generator type to allow specifying multiple module paths to generate from a single source.

Example:

source:
  git:
    url: https://github.com/some/repo
    commit: v42.0.0
    generate:
      gomod:
        paths:
          - .
          - some/subpath
          - some/other/subpath

Where the implied default with no paths are specified is the working directory, e.g. ["."]

Are you willing to submit PRs to contribute to this feature request?

• [ ] Yes, I am willing to implement it.