Probe Tip Etching Documentation In Progress

If you want a preview, here's a link to the Probe making documentation:

https://github.com/VikOlliver/RepRapMicron/wiki/Probe-Tip-Fabrication-And-Assembly

I've only covered the etching part so far, but I'll write proper docs for putting the etched tip on the Probe Arm later.

As an aside, I tried using the automated probe dipping with a variety of over- and under-etch roughened wires (by time and acid strength) and they generally end up with pretty much the same shape on the last 100μm:

 

As far as I can tell at this point, the upper profile is preferred.