docs: add returning on the first error example for try_join!
/// }
/// }
/// ```
+///
+/// Using `try_join!` with spawned tasks.
+///
+/// ```
+/// use tokio::task::JoinHandle;
+///
+/// async fn do_stuff_async() -> Result<(), &'static str> {
+/// // async work
+/// # Err("failed")
+/// }
+///
+/// async fn more_async_work() -> Result<(), &'static str> {
+/// // more here
+/// # Ok(())
+/// }
+///
+/// async fn flatten<T>(handle: JoinHandle<Result<T, &'static str>>) -> Result<T, &'static str> {
+/// match handle.await {
+/// Ok(Ok(result)) => Ok(result),
+/// Ok(Err(err)) => Err(err),
+/// Err(err) => Err("handling failed"),
+/// }
+/// }
+///
+/// #[tokio::main]
+/// async fn main() {
+/// let handle1 = tokio::spawn(do_stuff_async());
+/// let handle2 = tokio::spawn(more_async_work());
+/// match tokio::try_join!(flatten(handle1), flatten(handle2)) {
+/// Ok(val) => {
+/// // do something with the values
+/// }
+/// Err(err) => {
+/// println!("Failed with {}.", err);
+/// # assert_eq!(err, "failed");
+/// }
+/// }
+/// }
+/// ```
#[macro_export]
#[cfg_attr(docsrs, doc(cfg(feature = "macros")))]
macro_rules! try_join {
