Incorporate the suggestion of the separate "components" field, that will
hold references to resources of `Component` kind. Also, add a missing
reference to the base, in the Kustomization files of the variants.
The main change in this commit is that we rename the
`KustomizationPatch` kind to `Component`, and use the appropriate group
and API version (`kustomize.config.k8s.io/v1alpha1`).
Describe in more detail the solution with stock kustomize variants to
better showcase the benefits of kustomize components.
Plus, revamp certain parts of the example with minor fixes.
