Adjustable BLTouch front mount for Wanhao i3

This is an adjustable bracket to attach a BLTouch probe to the X carriage of a version 2.1 Wanhao Duplicator i3 and its clones (Monoprice Maker Select, Cocoon Create, etc.)

This Thing only provides the physical mount for the probe, and this writeup does not cover other aspects of getting a BLTouch probe installed and working in a Wanhao i3, such as wiring, firmware configuration, and controller board modification or replacement.

Note that this mod requires the removal of the stock front cooling fan and duct. If you're running one of the popular cooling mods like Thorped, Diiicooler, etc. then this is already taken care of.

**Design goals:**

* Minimize X and Y probe offset from hotend (to maximize range of bed mesh probing)
* Maximize Z height of BLtouch when pushed to the top
* Keep probe as rigid and level as possible
* Keep the probe from getting tilted/skewed during Z height adjustment
* Cleanly handle routing for the BLTouch wires

**Required hardware:**

_BLtou