Add "Retired" type to "Robot Control"

Author: per1234

registry.txt

@@ -9,7 +9,7 @@ https://github.com/arduino-libraries/Esplora.git|Arduino|Esplora
 https://github.com/arduino-libraries/Ethernet.git|Arduino|Ethernet
 https://github.com/arduino-libraries/GSM.git|Arduino,Retired|GSM
 https://github.com/arduino-libraries/LiquidCrystal.git|Arduino|LiquidCrystal
-https://github.com/arduino-libraries/Robot_Control.git|Arduino|Robot Control
+https://github.com/arduino-libraries/Robot_Control.git|Arduino,Retired|Robot Control
 https://github.com/arduino-libraries/RobotIRremote.git|Arduino,Retired|Robot IR Remote
 https://github.com/arduino-libraries/Robot_Motor.git|Arduino|Robot Motor
 https://github.com/arduino-libraries/RTCZero.git|Arduino|RTCZero