revC3: Marked non schematic/bom parts correctly.

revC3: Use the new KiCad DNP flag for the DNP parts.

revC3: Corrected U2 (CAT24M01) part number.

revC3: Final cleanups before production. * Changed 3D models to step so the 3D model can be exported for enclosure CAD. * Changed silk and stop colors to match 1BitSquared production boards

revC3: Hid U12&U21 labels. Corrected APX 1b2 key.

revC3: Increased min pad gap to 0.22mm. This increases the chances of getting solder mask bridges between pads decreasing probability of bridging.

revC3: Updated to the new stable KiCad V6. This includes updating the KiCad system 3D model library path variable.