Create a XML Schema for a catalog of cars, where each car has the child elements make, model, year, color, engine, number_of_doors, transmission_type, and accessories. The engine element has the child elements number _of_cylinders and fuel_system (carbureted or fuel_injected). The accessories element has the attributes radiio, air_conditioning, , power_windows, Power_steering, and Power_brakes, each of which is required and has the possible values of yes and no.