Add VIN voltage sensor ::class

[Juanduino]

In order to use a brake resistor, the lib need a VIN voltage class and actuator. (analog read pin for voltage divider and pwm out pin for MOSFET turn on turn of resistor burn pwm freq. The PWM frequency should not necessarily be the same as phase PWM frequency.

[Juanduino]

[runger1101001]

I think it will be useful to have a 1-input analog in class, for bus current sensing or battery voltage monitoring, or as you suggest for a brake resistor.

In terms of the PWM and control of the brake resistor, this sounds more difficult, requiring deeper integration into the library.