AP_RSSI: make metadata more consistent

libraries/AP_RSSI/AP_RSSI.cpp

@@ -48,7 +48,7 @@ const AP_Param::GroupInfo AP_RSSI::var_info[] = {
 
     // @Param: ANA_PIN
     // @DisplayName: Receiver RSSI sensing pin
-    // @Description: Pin used to read the RSSI voltage or PWM value
+    // @Description: Pin used to read the RSSI voltage or PWM value. Analog Airspeed ports can be used for Analog inputs (some autopilots provide others also), Non-IOMCU Servo/MotorOutputs can be used for PWM input when configured as "GPIOs". Values for some autopilots are given as examples. Search wiki for "Analog pins" for analog pin or "GPIOs", if PWM input type, to determine pin number.
     // @Values: 8:V5 Nano,11:Pixracer,13:Pixhawk ADC4,14:Pixhawk ADC3,15:Pixhawk ADC6/Pixhawk2 ADC,50:AUX1,51:AUX2,52:AUX3,53:AUX4,54:AUX5,55:AUX6,103:Pixhawk SBUS
     // @User: Standard
     AP_GROUPINFO("ANA_PIN", 1, AP_RSSI, rssi_analog_pin,  BOARD_RSSI_ANA_PIN),