Fix bugs of rev0 and create rev1 for Proto II/Mark I

[forGGe]

During the testing of Proto II, a number of issues has been found.

Following items must be addressed in rev.1 of the Proto II

• [x] Check markings near R201 (overlap with via).
• [x] A and B channels RS485 are swapped (bring it back)
• [x] Check markings C105
• [x] R304 and C301 markings should be swapped
• [x] RX/TX diodes must be reversed, or they should be tied to +3v3 (lid only when in transmit)
• [x] Reorient diodes and resistors to prevent bridges
• [x] Better way to switch 120 ohm on and off
• [x] Get rid of 5V-variant network
• [x] Make test points smaller
• [x] Add test points for BOOT0/BOOT1, SWDIO/SWCLK/SWGND, DE/~RE
• [x] Swap UART1 and UART2 - UART1 can be used for flashing a board, better use this as a debug UART (SEE NOTE BELOW)
• [x] No need in two RE/~DE optocouplers - can be used one and split right before ST485
• [x] Think even further - check ADUMXXX prices with 3 channels instead of 2.
• [ ] Better place connectors, so wires won't overlap with high profile components
• [x] Use SPST toggle in place of boot0 and tie boot1 to GND.
• [x] Use generic components in BOM (0603 LED, etc.) - make sure they match partsbox names
• [x] Add fiducials
• [x] Put designators near each LED, denoting its purpose
• [x] Optimize BOM for assembly in jlcpcb
• [ ] Apply software tweak to support both revisions at build time

[forGGe]

• [x] Swap UART1 and UART2 - UART1 can be used for flashing a board, better use this as a debug UART

UART2 is not 5V tolerant. Instead, UART3 is used in place of UART1.

So, UART1 will be used for debugging purposes, UART3 will be used for communicating with RS485 transceiver.