Replacement PCB for Viper/Eagle V2/V3

Fully tested and implemented. QMK and VIA added to main branch.

• QMK & VIA main repos
• USB C
• APM or STM32F072
• In-switich leds
• ISO and ANSI
• Underglow true to the original PCB

• Rev A1: Initial prototype
• Rev B1: Changing to USB-C, adding split space, changing MCU and adding transistors for indicators
• Rev B2: Adjusting PCB outline around the USB-port for a slimmer fit.
• Rev B3: Increasing polarity markings for leds on silkscreen. Align rotations with JLC. Add decoupling caps for supporting WS2812E.