Add embassy-boot

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.

embassy-boot/boot/Cargo.toml

@@ -0,0 +1,23 @@
+[package]
+authors = [
+    "Ulf Lilleengen <lulf@redhat.com>",
+]
+edition = "2018"
+name = "embassy-boot"
+version = "0.1.0"
+description = "Bootloader using Embassy"
+
+[lib]
+
+[dependencies]
+defmt = { version = "0.3", optional = true }
+log = { version = "0.4", optional = true  }
+embassy = { path = "../../embassy", default-features = false }
+embedded-storage = "0.3.0"
+embedded-storage-async = "0.3.0"
+
+[dev-dependencies]
+log = "0.4"
+env_logger = "0.9"
+rand = "0.8"
+futures = { version = "0.3", features = ["executor"] }