Provide container image for the user

[kaovilai]

So this step can become optional.

openshift-ops-workshops/README.md

Lines 78 to 85 in d0ecba8

	Next, Build a container using the repo/branch you checked out.
	```shell
	cd openshift-ops-workshops
	export QUAY_USER=myusername
	export BRANCH=$(git branch --show-current)
	podman build -t quay.io/${QUAY_USER}/lab-sample-workshop:${BRANCH} .
	```

Can be done as part of GitHub Actions build on push (for each branch) if Dockerfile changed to publish on quay.io or ghcr.io