Publish latest code to Docker Hub?

(Extracted from a sub-item in #63)

It would be great if the latest code in this repo could be published as a multi-architecture `linux/amd64,linux/arm64` Docker image to https://hub.docker.com/r/sgerrand/glibc-builder, replacing the version there that's ~5 years old, so that consumers of this repo don't have to build this Docker image themselves.

Might this be feasible, please?