message: docs: fix install global subscriber example in README.md
diff: @@ -59,7 +59,7 @@ use tracing_subscriber;
  fn main() {
  // install global subscriber configured based on RUST_LOG envvar.
  - tracing_subscriber::init();
  + tracing_subscriber::fmt::init();
  let number_of_yaks = 3;
  // this creates a new event, outside of any spans.
  