programs are rendered after LEDs are sent. this means the first update would be garbage. initialize the data so this is not the case.
also fix bug with current scaling register fill function (doesn't affect this program).
several issues with the bootloader, from gpio config, UART baud, etc.
bootloader now does the following:
- enters bootloader mode upon holding BTN2 at power-up
- flashes LED4 rapidly to indicate in bootloader mode
- operates WCH ISP bootloader at 115200 baud on the UART pins on GAT header
true