Changed the return type of detect_language to Option to account for empty strings.
Applied cargo format
@fulmicoton This change was convenient when adding Whichlang to https://github.com/whatlang/whatlang-accuracy-benchmark. I think it was also reported by @fmassot but please, ignore it if it's not in the spirit of this crate.
detect_language
toOption
to account for empty strings.