Fix clap_app! usage example
I found this usage example confusing because `matches` was actually an `App`
@@ -262,7 +262,8 @@ macro_rules! app_from_crate {
/// (author: "Someone E. <someone_else@other.com>")
/// (@arg verbose: -v --verbose "Print test information verbosely")
/// )
-/// );
+/// )
+/// .get_matches();
/// # }
/// ```
///
