Allow option to build image with Docker buildx Bake

It would be great to allow the option to use Docker's Bake cli tool to build images as well.
https://docs.docker.com/engine/reference/commandline/buildx_bake/

In my repos, we're using bake internally to build images (including sourcing remote docker bake files), it would be great to have this option as well so we could have parity with devcontainers.

Could potentially be merged with this feature request on allow extra flags to the buildx command https://github.com/devcontainers/spec/issues/85

Thanks!