Fix code example to match help text
@@ -2411,7 +2411,8 @@ impl<'help> Arg<'help> {
/// let m = App::new("prog")
/// .arg(Arg::new("config")
/// .long("config")
- /// .value_name("FILE"))
+ /// .value_name("FILE")
+ /// .about("Some help text"))
/// .get_matches_from(vec![
/// "prog", "--help"
/// ]);
