Games/Racing: Add Dr. Robotnik's Ring Racers (luong-komorebi#821)

README.md

@@ -726,6 +726,7 @@ _For a more comprehensive/advanced/better categorized/... list of Linux audio so
 
 #### Racing
 
+- [![Open-Source Software][oss icon]](https://github.com/KartKrewDev/RingRacers/) [Dr. Robotnik's Ring Racers](https://www.kartkrew.org/) - A technical kart racer, drawing inspiration from “antigrav” racers, fighting games, and traditional-style kart racing.
 - [![Open-Source Software][oss icon]](https://motogt.sourceforge.net/) [MotoGT](https://motogt.sourceforge.net/) - 2D top-viewed game where you drive a MotoGP bike.
 - [![Open-Source Software][oss icon]](https://github.com/supertuxkart/stk-code) [SuperTuxKart](https://supertuxkart.net) - SuperTuxKart is a 3D open-source arcade racer with a variety characters, tracks, and modes to play.
 - [![Open-Source Software][oss icon]](https://xmoto.tuxfamily.org/index.php) [XMoto](https://xmoto.tuxfamily.org/) - 2D motocross physics-based game requiring a lot of skill to master, with a built-in replay-recording and sharing system.