Update Kubernetes example yaml files (#5278)

Removed the non production ready Kubernetes constructs that are not needed
for standard Minio deployment. General cleanup of the documents.

docs/orchestration/kubernetes-yaml/minio-standalone-service.yaml

@@ -1,6 +1,7 @@
 apiVersion: v1
 kind: Service
 metadata:
+  # This name uniquely identifies the service
   name: minio-service
 spec:
   type: LoadBalancer
@@ -9,4 +10,5 @@ spec:
       targetPort: 9000
       protocol: TCP
   selector:
+    # Looks for labels `app:minio` in the namespace and applies the spec
     app: minio