Infrared RCA Protocol + Update docs

Thanks to anonymous contributor for protocol implementation and testing

lib/infrared/encoder_decoder/infrared.h

@@ -33,6 +33,7 @@ typedef enum {
     InfraredProtocolSIRC15,
     InfraredProtocolSIRC20,
     InfraredProtocolKaseikyo,
+    InfraredProtocolRCA,
     InfraredProtocolMAX,
 } InfraredProtocol;