I may need to introduce a new concept to Datasette for this - maybe a way of telling it to pick up certain plugin settings from environment variables. ```json { "title": "datasette-auth-github demo", "plugins": { "datasette-auth-github": { "client_id": "986f5d837b45e32ee6dd", "client_secret": {"$env": "GITHUB_CLIENT_SECRET"} } } } ```