RN8209 energy sensor support with watt, voltage and current. (#1337)

Co-authored-by: h2zero <powellperalta@gmail.com>

docs/use/sensors.md

@@ -12,9 +12,6 @@ You will receive every TimeBetweenReadingDHT (set into config_DHT.h) the DHT mea
 
 `home/OpenMQTTGateway/DHTtoMQTT {"tempc":21,"tempf":69.8,"hum":51}`
 
-Legacy (removed after release 0.9.5)
-`home/OpenMQTTGateway/DHTtoMQTT {"temp":21,"hum":51}`
-
 If you want to don't resend value when it is the same you can set dht_always = false in config_DHT.h
 
 ### HTU21
@@ -37,9 +34,6 @@ Each sensor will be published under the following topic using each sensors' addr
 
 `home/OpenMQTTGateway/CLIMAtoMQTT/ds1820/0x0000000000000000 {"tempc":27.8, "tempf":82.04, "type":"DS18B20","res":"12bit\n","addr":"0x28616411907650bc"}`
 
-Legacy (removed after release 0.9.5)
-`home/OpenMQTTGateway/CLIMAtoMQTT/ds1820/0x0000000000000000 {"temp":27.8,"unit":"C","type":"DS18B20","res":"12bit\n","addr":"0x28616411907650bc"}`
-
 The units for temperature readings are sent in Celsius by default can be changed to Fahrenheit by setting DS1820_FAHRENHEIT = true in in config_DS1820.h
 
 If you don't want to resend values that haven't changed you can set DS1820_ALWAYS = false in config_DS1820.h
@@ -55,4 +49,9 @@ This can be useful if you would like to connect an LED to turn on when motion is
 `#define HCSR501_LED_NOTIFY_GPIO 4`
 
 This notification pin can be inverted if driving directly or through a transistor/mosfet.
-`#define INVERT_LED_NOTIFY true`
+`#define INVERT_LED_NOTIFY true`
+
+### RN8209
+You will receive every TimeBetweenReadingRN8209 (set into config_RN8209.h) the RN8209 measurements (10s per default).
+
+`home/OpenMQTTGateway/RN8209toMQTT {"volt":120.345,"current":7.9264,"power":954.6132}`