Draft: Nano Convertor Plate: Allow for Inland brand stepper controller boards, configurable options for microcontroller and brim

This PR allows for easy configuration of the Nano Convertor Plate to allow for different microcontrollers (Arduino Nano and the Raspberry Pi) as well as different stepper motor controller boards (Standard stepper controller board and the smaller Inland brand controller board that came with my steppers from Microcenter).

The configuration options are specified in the openscad/nano_convertor_plate.scad file for now.

In addition to the above configurability, this version includes a set of troughs for the Raspberry Pi Pico through hole soldering to seat into.

Although this has been printed, it has not been tested. I have done a fit test of the stepper driver controller boards and it is a bit tight (could stand to be loosened up just a bit).

The following is an example with the Raspberry Pi Pico and the Inland style stepper controller boards