message: Throw correct error when an unimplemented command is used with arguments
  Fixes
diff: @@ -632,7 +632,7 @@ function nameParser(
  name: [string, string],
  argParser: ArgParser | undefined
  ): Parser<Parser<ExCommand>> {
  - argParser ??= succeed(new UnimplementedCommand(name[1] ? `${name[0]}[${name[1]}]` : name[0]));
  + argParser ??= all.result(new UnimplementedCommand(name[1] ? `${name[0]}[${name[1]}]` : name[0]));
  const fullName = name[0] + name[1];
  const p = nameAbbrevParser(name[0], name[1]).result(argParser);
  