Merge branch 'master' into HMAC-secret-extension

.cargo/config

.github/workflows/boards_build.yml

.vscode/settings.json

README.md

boards/nrf52840_dongle_dfu/Cargo.toml

boards/nrf52840_dongle_dfu/Makefile

boards/nrf52840_dongle_dfu/build.rs

boards/nrf52840_dongle_dfu/layout.ld

boards/nrf52840_mdk_dfu/Cargo.toml

boards/nrf52840_mdk_dfu/Makefile

boards/nrf52840_mdk_dfu/build.rs

boards/nrf52840_mdk_dfu/layout.ld

boards/nrf52840_mdk_dfu/src/io.rs

boards/nrf52840_mdk_dfu/src/main.rs

deploy.py

docs/install.md

patches/tock/04-nrf52-bootloader.patch

setup.sh