update readme

README.md

@@ -192,7 +192,7 @@ using msghandler, NATS
 
 conn = NATS.connect("nats.yiem.cc")
 NATS.subscribe(conn, "test.topic") do msg
-  log_trace("Received message on $(msg.subject)")
+  println("Received message on $(msg.subject)")
   
   # Use NATSBridge.smartreceive to handle the data
   # API: smartreceive(msg, download_handler; max_retries, base_delay, max_delay)
@@ -202,6 +202,7 @@ NATS.subscribe(conn, "test.topic") do msg
     base_delay = 100,
     max_delay = 5000
   )
+  println(envelope.payloads[1])
 end
 ```