feat: allow set some heading

[eatradish]

Like:

fn main() {
    use clap::Command;
    Command::new("myprog")
        .arg(
            Arg::new("test")
                .long("test")
                .action(ArgAction::SetTrue)
                .visible_alias("b")
                .aliases_heading("又叫")
        )
        .print_help()
        .unwrap();
}

Will output:

Usage: myprog [OPTIONS]

Options:
      --test  [又叫: --b]
      -h, --help  Print help