Macro pw_log::warn

macro_rules! warn {
    ($($args:expr),*) => { ... };
}

Emit a warn level log message using core::fmt format string semantics.

use pw_log::warn;

warn!(
    "Log Fact: Made from a log, an {} year old dugout canoe is the oldest discovered boat in {}.",
    8000 as i32, "Africa" as &str);