Prusa i3 Bltouch Upgrade

### Description
The 3dprintingstore.co.za Prusa i3 uses a micro switch on a servo with the auto bed-leveling upgrade kit. I really like the auto bed leveling feature but never really trusted the repeatability of the switch on the servo.

This is an upgrade to replace the servo mounted micro switch with a bltouch sensor. Wiring of the Bltouch is great, you directly replace the servo and z end stop connectors with the matching cables on the Bltouch. Reference the attached image.

I included two files to support both E3Dv5 and E3Dv6 hotends. The height of these hot ends differ by 7mm and the Bltouch need to be mounted accordingly, ensure you use the correct model for your hotend, the printer ship with an E3Dv5 hotend.

Note: I have not tested the E3Dv5 version. Let me know if I need to make some corrections.

### Firmware Settings

In addition you will need to make the necessary changes in the firmware configuration.h. I used the marlin firmware supplied by 3dprintingstore.co