add interrupt example

docs: Add section for serial flashing

Add section to describe flashing firmware over a serial connection

Update LED Shell example

update debugger config

Update dependencies, release v0.3.0

Make converting SD card frequency easier

Use the full screen size to draw the rectangle to clear the screen

Update LCD libraries

Add support for sdcard

Co-authored-by: Vadim Kaushan <admin@disasm.info>

Serial shell example

Add instructions to skip the risc-v toolchain (plus arm64 support)

Add documentation for dfu-util based flashing

Update to embedded_graphics V0.6 and st7735 V0.7

add new method to each rgb led

Fix LCD window offset (0, 26) -> (1, 26)