register an option that can be as the argument of command line. remember that it is positional sensitive and if you want to registered a variadic option, this option must be registered at the end and not other variadic options to be registered
the option's name or its long/short flag to be registered
the rest be registered
Self for chain call
See Implementation
register an option that can be as the argument of command line. remember that it is positional sensitive and if you want to registered a variadic option, this option must be registered at the end and not other variadic options to be registered