Useful Link to learn websocket & MQTT
- https://www.espruino.com/MQTT -- -- -- mqtt functions
- https://www.ably.io/documentation/mqtt ----- Publishing and Subscribing with MQTT
- https://www.hivemq.com/mqtt-essentials/ - mqtt-essentials
- https://www.linode.com/docs/development/introduction-to-websockets/
- https://webplatform.github.io/docs/apis/websocket/
