devcontainers-features/test/_global/scenarios.json

{
    "color_and_hello": {
        "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
        "features": {
            "color": {
                "favorite": "purple"
            },
            "hello": {
                "greeting": "Greetings"
            }
        }
    }
}