public HelpPrinter option(String longName, String shortName, String description) {
        args.add(Arg.option(longName, shortName, description));
        return this;
    }
Adds an option that takes no argument value.

@param longName Nullable argument long form (e.g., "--foo").
@param shortName Nullable argument short form (e.g., null).
@param description Description description of the argument.
@return Returns the printer.
smithy-cli/src/main/java/software/amazon/smithy/cli/HelpPrinter.java