Hosted container services such as Azure Container Images are broken
by the absence of metadata in images pushed by Skopeo. Using Docker we
can push and ensure all metadata is in place.
Tested on: GitHub Actions for black-river-software/urbit fork.
When pushing the docker image, update the "latest" tag as well as
pushing a tag for the current Urbit version. This way users pulling
tloncorp/urbit:latest will always get an image with the latest point
release of Urbit.
d3c5aa74c1 introduced a Docker image intended for deploying Urbit ships
This commit modifies the build.yml GitHub Actions workflow to build the
docker image as part of the push/PR workflow, and adds a
`release-docker.yml` workflow, which runs on any tag push `urbit-v*` and
pushes the image to Docker Hub, also synchronizing the README.
Co-authored-by: Josh Lehman <josh@urbit.org>