Incorrectly parses shorthand with suffix e.g. "@dailyBla"

[geovie]

Hi, first thanks for this crate. When testing it I've found that a shorthand (e.g. @weekly) followed by any characters (e.g. @weeklyFoo) will be parsed as @weekly.

To be more strict it probably should return an error in this case or what do you think?

[zslayton]

Thanks for reporting this. I agree that superfluous trailing characters should be rejected with an error.