RFC: "Announce" entry from GitHub repository

So here's a simply workflow to allow a developer to submit an entry to Homebrew Hub simply "announcing" the git repository:

- The developer creates a github repository hosting all the game files / sources etc AND a `game.json` manifest
- Developer opens an issue in the database repository mentioning he wants to add a game and links the repository
- An automated action picks up the issue and imports the folder in the database, in the current status. If the validation fails, it reports in the issue what went wrong. Validation steps:
- game.json schema validation
- file validation

Open questions:
- How can the developer refer to the ROM if it's not in the git repo but e.g. in the releases?