Embassy-boot is a simple bootloader that works together with an
application to provide firmware update capabilities with a minimal risk.
The bootloader consists of a platform-independent part, which implements
the swap algorithm, and a platform-dependent part (currently only for
nRF) that provides addition functionality such as watchdog timers
softdevice support.
This allows writing drivers relying on async traits, while still
functioning with implementations that already implement the embedded-hal
traits.
Add examples to stm32l4 for using this feature.
