Add contributions on a per-subdirectory basis to better describe monorepo package maintainers

Is your feature request related to a problem? Please describe.

The Carbon Design System primarily uses monorepos, where each repo includes multiple packages. We're looking to recognize contribution in general, but also specify maintainers on a per-package basis.

Describe the solution you'd like

When using the maintenance key (or any key for that matter), be able to specify if that key is specific to a subdirectory of the repo. For example, maybe something like this:

{
  "projectName": "carbon",
  "projectOwner": "carbon-design-system",
  "repoType": "github",
  "repoHost": "https://github.com",
  "contributors": [
    {
      "login": "username",
      "name": "User Name",
      "profile": "https://github.com/username",
      "contributions": [
        "code",
        "doc",
        "infra",
        "review",
        "maintenance"
      ]
    }
  ]
}

Could be more specific like:

{
  "projectName": "carbon",
  "projectOwner": "carbon-design-system",
  "repoType": "github",
  "repoHost": "https://github.com",
  "contributors": [
    {
      "login": "username",
      "name": "User Name",
      "profile": "https://github.com/username",
      "contributions": [
        "code",
        "doc",
        "infra",
        "review",
        {
          "key": "maintenance",
          "subDirectories": [
            "packages/react",
            "packages/styles"
          ]
        }
      ]
    }
  ]
}

Describe alternatives you've considered

1. List GitHub teams / users in CODEOWNERS file and then write a custom solution to use GitHub APIs to fetch team members and user information to determine maintainers on a package basis.
2. Manually list names of maintainers in READMEs in each package's folder.

How would that look like on the (overall) table?

How would that look like on the (overall) table?

I would keep it simple and render the same way on the main table. You could get fancy, but there's probably no need.