message: Add a remark to section off the input fields.
diff: @@ -18,6 +18,7 @@ pub struct Cli {
  /// files.
  #[structopt(long, group = "format_choice")]
  format_file: Option<PathBuf>,
  + // The (binary) input files to operate on:
  /// The path to the file(s) to parse
  #[structopt(parse(from_os_str))]
  files: Vec<PathBuf>,
  