added more for readme

dsh_mqtt_client/README.md

@@ -1,4 +1,12 @@
+# dsh_mqtt_client
+
 ## Run the example
 
 To run the example for fetching mqtt token, you may use below command:
-cargo run --package dsh_mqtt_client --example main
+cargo run --package dsh_mqtt_client --example fetch_token
+
+To run the example for publishing a message, you may use below command:
+cargo run --package dsh_mqtt_client --example publish
+
+To run the example for fetching mqtt token, you may use below command:
+cargo run --package dsh_mqtt_client --example subscribe