README doesn't explain how to build container

[pcm32]

The README doesn't really explain how to build that docker image. The repo doesn’t have a Dockerfile, yet all explanations are with docker build. I’m guessing you need to use the ansible playbook there, but it could be great if the readme would be explicit about what are those steps. Thanks!

[almahmoud]

The Dockerfile was moved to the Galaxy repo itself to make it easier, so this documentation is now out of date.
All you need to do is clone galaxy and do docker build . -f ./.k8s_ci.Dockerfile also, an image is built automatically with every commit to dev branch at galaxy/galaxy-min:latest