Create an Arduino Class, to control stepper motors, max. 6 in total, via potentiometers. There's one additional potentiometer to control speeds of all motors, using multiplication. Dont wrap it as Markdown, output just the code.

- Use MultiStepper class of the AccelStepper library
- add an example Arduino program
- dont add notes
- each motor has 2 parameters, direction and pulse, and one for the potentiometer pin, define a struct for this
- the controller's main function is called 'loop', and the initialization 'setup'
- optimize the class and it's types for low-memory consumption
- it's for ESP-32
- place all constants at the top, max acceleration, max speed, etc.
- dont use moveTo or distanceToGo, use setSpeed

Wrap the motor controller in another class, and adding this functions

- add 2 analog inputs, to start and stop the motors. let me specify the threshold as constant
- add 2 digital ouputs for LED feedback, eg: PIN_LED_ON, PIN_LED_OFF
- add a function to query the speed for each motor