Add some more docs about building images
Add some more docs about building images

Add some more examples on how to use podman for cri-o runtime,
and how to use buildctl (with buildkitd) for containerd runtime.

kubernetes/minikube,kubernetes/minikube,kubernetes/minikube,kubernetes/minikube,warmchang/minikube,kubernetes/minikube,warmchang/minikube,warmchang/minikube,kubernetes/minikube,warmchang/minikube,warmchang/minikube,warmchang/minikube,kubernetes/minikube,warmchang/minikube