feat: move kubernetes dir into templates to support jinja2 across all files (#831)

template/templates/kubernetes/apps/system-upgrade/kustomization.yaml.j2

@@ -0,0 +1,9 @@
+---
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+resources:
+  - ./namespace.yaml
+  # NOTE: Only enable system-upgrade-controller if you also update the version of k3s in the following file
+  # otherwise if you run ansible against an already provisioned cluster you might downgrade it
+  # https://github.com/onedr0p/flux-cluster-template/blob/main/ansible/inventory/group_vars/kubernetes/main.yaml
+  # - ./system-upgrade-controller/ks.yaml