UART with IRQ + Embassy example

examples/embassy/src/bin/uart-echo-with-irq.rs

@@ -1,3 +1,12 @@
+//! This is an example of using the UART HAL abstraction with the IRQ support and embassy.
+//!
+//! It uses the UART0 for communication with another MCU or a host computer (recommended).
+//! You can connect a USB-to-Serial converter to the UART0 pins and then use a serial terminal
+//! application like picocom to send data to the microcontroller, which should be echoed
+//! back to the sender.
+//!
+//! This application uses the interrupt support of the VA416xx to read the data arriving
+//! on the UART without requiring polling.
 #![no_std]
 #![no_main]
 use core::cell::RefCell;