Update src/async.rs

Co-authored-by: Leonardo L. <[email protected]>

src/async.rs

@@ -456,7 +456,7 @@ fn is_status_retryable(status: reqwest::StatusCode) -> bool {
 /// Trait that defines the ability to sleep within an async runtime
 #[async_trait]
 pub trait Sleeper {
-    /// Wait until the specified `duration` has elapsed
+    /// Sleeps until the specified `duration` has elapsed.
     async fn sleep(duration: Duration);
 }