Publish to nodejs/devcontainer rather than bnb/devenv

[bnb]

presently, we're publishing the docker image to bnb/devenv on Docker Hub. Ideally, we'd be able to change that to publishing to nodejs/devcontainer on Docker Hub.

We'd need to add correct secrets (cc @nodejs/docker) to this repo, which would be consumed by the build and publish action here.

Further, we'd want to update the tags here to nodejs/devcontainer:latest.

[bnb]

Just a note that this isn't stalled, we're just waiting on getting ownership of an organization :)

[bnb]

update: secrets are in the repo, action is running now. This should work.

[bnb]

done :)