Add badges for Java version and platform

Added Java and Platform badges to README.

Author: javiergs

README.md

@@ -1,5 +1,7 @@
 ![Static Badge](https://img.shields.io/badge/author-javiergs-orange)
 ![GitHub repo size](https://img.shields.io/github/repo-size/CSC3100/Tool-MQTT)
+![Java](https://img.shields.io/badge/Java-17+-blue)
+![Platform](https://img.shields.io/badge/platform-Java_Swing-orange)
 
 This project provides three Java examples for learning MQTT using the Eclipse Paho MQTT client and the public test broker at **test.mosquitto.org**.