Replace pin by gpio (#631)

* replace _PIN by _GPIO

* add mention about the goal of -all binaries

* [breaking] change json key from "pin" to "gpio" for actuatorONOFF

docs/use/actuators.md

@@ -3,7 +3,7 @@
 This module enables to actuate things by giving to a PIN a HIGH or LOW value corresponding to an MQTT topic.
 Example usage: Connect a transistor to power a relay, connect a led...
 
-So as to pilot the pin use the following commands with [simple receiving](../upload/pio.md#api):
+So as to pilot the GPIO use the following commands with [simple receiving](../upload/pio.md#api):
 
 OFF command:
 `mosquitto_pub -t home/OpenMQTTGateway_MEGA/commands/MQTTtoONOFF/setOFF -m 15`
@@ -14,10 +14,10 @@ ON command
 or with [json receiving](../upload/pio.md#api)
 
 OFF command:
-`mosquitto_pub -t home/OpenMQTTGateway_MEGA/commands/MQTTtoONOFF -m '{"pin":15,"cmd":0}'`
+`mosquitto_pub -t home/OpenMQTTGateway_MEGA/commands/MQTTtoONOFF -m '{"gpio":15,"cmd":0}'`
 
 ON command
-`mosquitto_pub -t home/OpenMQTTGateway_MEGA/commands/MQTTtoONOFF -m '{"pin":15,"cmd":1}'`
+`mosquitto_pub -t home/OpenMQTTGateway_MEGA/commands/MQTTtoONOFF -m '{"gpio":15,"cmd":1}'`
 
 ## FASTLED
 ### The FASTLED module support 2 different operation modes