SKR Mini E3 bltouch with standard mount E3 firmware source

For use on an Ender 3 or Ender 3 Pro with a bltouch and mount for the standard fan shroud. https://www.thingiverse.com/thing:3003725 Marlin 2.0 bugfix setup for Ender 3 and the SKR Mini E3 mainboard.

Reference video: https://youtu.be/-XUQKQnUNig

This is currently untested on the new 1.2 boards.