v2.0 routing and layout changes

In testing the v1.0 board I realised I had the SPI signals routed to the flash memory pins of the ESP8266, which made everything break. I did some tests on that initial board with some wire mods, and confirmed which pins I actually needed to use. This revision of the PCB fixes those problems.

I also updated to use the footprint from JLCPCB for the ESP12E module, to make it easier to use their PCBA service.