Add recommended print settings for the case

[KasimAhmic]

I'm currently about half way through printing the bottom left portion of the case and have just noticed that the case will be about 0.1mm off dimension because I printed it at 0.2mm layer heights and the height of the model 12.5mm. To be clear, this isn't a huge concern given the general inaccuracies of 3D printing and the small difference but it would've been nice to know ahead of time that I could've printed it at 0.3mm layer heights and saved about 2 hours of print time.

It would be nice to have the suggested print settings in the README so that there's no guess work involved. Something like this should suffice:

Property	Value
Material	___
Nozzle Diameter	___ mm
Layer Height	___ mm
Perimeter	___
Infill	___ %

This way, we have a simple enough baseline to go off of so that we can further tweak the print settings or just use one of the many print profiles that slicers include these days.