Add a new example for defmt use

Signed-off-by: Daniel Egger <[email protected]>

Author: therealprof

examples/defmt.rs

@@ -0,0 +1,18 @@
+#![no_main]
+#![no_std]
+
+use panic_halt as _;
+use defmt_rtt as _;
+use defmt as _;
+
+use stm32f0xx_hal as _;
+
+use cortex_m_rt::entry;
+
+#[entry]
+fn main() -> ! {
+    defmt::println!("Hello, world!");
+    defmt::timestamp!("Hello, world!");
+
+    loop { }
+}