HASS gateway Discovery improvements (#792)

* MQTT discovery improvements

-remove gatewayBT
-remove device class formaldehyde (not existing in HASS)
-add SYStoMQTT new parameters
-attach connectivity parameter to the device
-add BT gateway infos and switches
-refactor modules storage and publication

docs/use/gateway.md

@@ -1,13 +1,20 @@
 # System commands (ESP only)
 
 ## Restart the ESP
-
 `mosquitto_pub -t "home/OpenMQTTGateway/commands/MQTTtoSYS/config" -m '{"cmd":"restart"}'`
 
+::: tip
+With Home Assistant, this command is directly avalaible through MQTT auto discovery as a switch into the HASS OpenMQTTGateway device entities list.
+:::
+
 ## Erase the ESP settings
 
 `mosquitto_pub -t "home/OpenMQTTGateway/commands/MQTTtoSYS/config" -m '{"cmd":"erase"}'`
 
+::: tip
+With Home Assistant, this command is directly avalaible through MQTT auto discovery as a switch into the HASS OpenMQTTGateway device entities list.
+:::
+
 # State LED usage
 
 The gateway can support up to 3 LED to display its operating state: