Add working USART1 initialization

Add bsp.hpp, add USART WIP

MainBoardBRD: route power supply parts Routed: - on/off power transistor Q1. Q2 - power supply step-ups - servos power supply - apply `robotikabrno.dru`

Remove HID thing from USB

Merge pull request #5 from RoboticsBrno/fw-cdc Add CDC loopback

Remove unneeded USB files

MainBoardBRD: change top side SMD parts footprint according IPC-7351 (using Library Expert Pro (2019.7) )

Add the CDC loopback demo, adjusted

Add adjusted libusb_stm32

Fix platformio.ini, remove unneeded directives