added msg

Author: BluffSet7340

billing-service/src/main/java/com/pm/billing_service/grpc/BillingGrpcService.java

@@ -10,7 +10,7 @@
 // tell string this is a grpc service
 @GrpcService
 public class BillingGrpcService extends BillingServiceImplBase {
-
+// this was not easy to understand at first I tell you what
     private static final org.slf4j.Logger log = 
     LoggerFactory.getLogger(BillingGrpcService.class);
     // stream observer allows back and forth communication between client and server as opposed to rest api that require you to repeatedly make api calls to communicate