It makes sense to add that as a CLI args since you could use one single
kustomization file/helm chart for multiple clusters. Also it's easier to
have those on the CLI if the user has some kind of tooling that will end
up calling kustomize and that could pass those (i.e.: ArgoCD is doing
that for Helm so it could do that for Kustomize as well that will end up
calling Helm as well).
Signed-off-by: Arthur Outhenin-Chalandre <arthur.outhenin-chalandre@ledger.fr>
