Completely setup kubectl for ansible_user, with option to disable it (#278)

Signed-off-by: Derek Nola <derek.nola@suse.com>

inventory-sample.yml

@@ -28,6 +28,7 @@ k3s_cluster:
     # List of locally available manifests to apply to the cluster, useful for PVCs or Traefik modifications.
     # extra_manifests: [ '/path/to/manifest1.yaml', '/path/to/manifest2.yaml' ]
     # airgap_dir: /tmp/k3s-airgap-images
+    # user_kubectl: true, by default kubectl is symlinked and configured for use by ansible_user. Set to false to only kubectl via root user.
     # server_config_yaml:  |
       # This is now an inner yaml file. Maintain the indentation.
       # YAML here will be placed as the content of /etc/rancher/k3s/config.yaml