Add support for rotary engines

Not sure if this is implemented by default, but would be cool to see rotary engines in the simulator some audi's and mazda's have rotary engines so it would be cool to be able to add them (might already be possible but I have 0 clue how creating engines works)

look at the existing ones at https://github.com/ange-yaghi/engine-sim/tree/master/assets/engines

Rotary engines are currently not possible. I'll tag this is a feature request.

Guys at mazda: aha spinny dorito goes brrrrrrrrr

@ange-yaghi should this be closed after your recent video? haha