hw_test: buzzer test

hw_test: USB test - redirected to debug USART, because of presence of DMA

hw_test: fix tunnel spelling

hw_test: add buttons and power

hw_test: LEDs test, fix pins manipulating (indexes vs masks)

hw_test: rename UARTs, add UARTs and their pins, systick interrupt blinks LED1 (not tested), add ST-LINK to platformio.ini

hw_test: migrate from bluepill to RBCX processor, fix Nanopb duplicity

hw_test: copy actual firmware from master

Merge pull request #15 from RoboticsBrno/hw_v1.0 Hw v1.0

hw: create folder `RBCX_v1.0` with manufactured Eagle PCB files