message: Print header when starting REPL
diff: @@ -15,6 +15,12 @@ fn main() {
  if let Err(_) = rl.load_history(REPL_HISTORY_FILE) {}
  + println!(
  + "{}, version {} (:? for help, :q to quit)",
  + env!("CARGO_PKG_NAME"),
  + env!("CARGO_PKG_VERSION"),
  + );
  +
  loop {
  match rl.readline(PROMPT) {
  Ok(line) => {
  