100mm Calibration Axes

I moved the stops on the ends of the X- and Y-axes further out so that you take all measurements with the depth stick (?) on your calipers. This removes extrusion thickness as a source of error for X and Y.

I also extended the Z-axis out to 100 mm for consistency. I printed this at 0.1 mm with a 0.2 mm first layer; 0.2 mm all around probably would've worked just as well, or any other combination of layer height (z) and first-layer height (zf) such that n*z+zf=100 for some integer value of n