Self-contained configuration documentation

[asoltesz]

Currently, we are referring to Vito's article about the configuration steps of the cluster building system, including Ansible, Terraform and shell variables.

The SolaKube documentation about the configuration should be standalone and self-contained, including all necessary steps to setup/configure a cluster to be built.

The solakube-andromeda git repo should also contain a sample "variables.sh" for being a complete example.