authelia: Set up OIDC for k8s API server

Enabling OpenID Connect authentication for the Kubernetes API server
will allow clients, particularly `kubectl` to log in without needing
TLS certificates and private keys.

authelia/oidc-cluster-admin.yaml

@@ -0,0 +1,12 @@
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: oidc-cluster-admin
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: cluster-admin
+subjects:
+- apiGroup: rbac.authorization.k8s.io
+  kind: User
+  name: oidc:dustin