Visualise maintainers

[john-rodewald]

We want an overview of maintainers - maybe we can leverage CODEOWNER files for this.

• Since the documentation team touches multiple repositories (nix.dev, nixpkgs), we need to parse multiple files.
• Not all entries should be visualised - especially not from the nixpkgs file. How do we match just maintainers?

[lucperkins]

@john-rodewald Do you by chance know of any tools that can provide a visualization like this? We on the docs team agree that this would be a cool thing to have but without a dedicated tool—and thus a clear path—it may not be sufficiently high value to warrant the work involved.