ManualControl: start to distinguish rc arming methods

src/modules/commander/commander_params.c

@@ -313,10 +313,11 @@ PARAM_DEFINE_FLOAT(COM_DISARM_PRFLT, 10.0f);
 PARAM_DEFINE_INT32(COM_ARM_WO_GPS, 1);
 
 /**
- * Arm switch is only a button
+ * Arm switch is a momentary button
  *
- * The default uses the arm switch as real switch.
- * If parameter set button gets handled like stick arming.
+ * 0: Arming/disarming triggers on switch transition.
+ * 1: Arming/disarming triggers when holding the momentary button down
+ * for COM_RC_ARM_HYST like the stick gesture.
  *
  * @group Commander
  * @boolean