message: Fix typo: substract -> subtract
diff: @@ -65,7 +65,7 @@ pub fn main(config: &mut Config) -> CliResult {
  .iter()
  .map(|(option_name, option_help_message)| {
  let option_name_kebab_case = option_name.replace("_", "-");
  - let padding = " ".repeat(longest_option - option_name.len()); // safe to substract
  + let padding = " ".repeat(longest_option - option_name.len()); // safe to subtract
  format!(
  " -Z {}{} -- {}",
  option_name_kebab_case, padding, option_help_message
  