Add more output when building images
I was trying to debug how a docker image was built, but noticed that none of the commands were showing any output:
As per https://docs.docker.com/engine/reference/commandline/build/#options (and https://stackoverflow.com/questions/64804749/why-is-docker-build-not-showing-any-output-from-commands) we can add --progress=plain to get the command output.
I think it's good to be more verbose here so we can always check what exactly happened during the build.