This setting defines the behaviour of the main LED in the board.<br/>
When in "WiFi status" it will blink at 1Hz when trying to connect. If successfully connected it will briefly blink every 5 seconds if in STA mode or every second if in AP mode.<br/>
When in "Relay status" mode the LED will be ON whenever any relay is ON, and OFF otherwise. This is global status notification.<br/>
When in "MQTT managed" mode you will be able to set the LED state sending a message to "<base_topic>/led/0/set" with a payload of 0, 1 or 2 (to toggle it).<br/>
When in "Find me" mode the LED will be ON when all relays are OFF. This is meant to locate switches at night.<br/>
When in "Status" mode the LED will be ON whenever any relay is ON, and OFF otherwise. This is global status notification.<br/>
When in "Mixed" mode it will follow the WiFi status but will stay mostly on when relays are OFF, and mostly OFF when any of them is ON.<br/>
When in "Relay & WiFi" mode it will follow the WiFi status but will stay mostly off when relays are OFF, and mostly ON when any of them is ON.<br/>
When in "Find me & WiFi" mode is the opposite of the "Relay & WiFi", it will follow the WiFi status but will stay mostly on when relays are OFF, and mostly OFF when any of them is ON.<br/>
"Always ON" and "Always OFF" modes are self-explanatory.