Unidecode maintainer here. I really need to add some commentary to that "Bei Jing" example in the README.
Unidecode doesn't do language-specific transliteration and really works best for user-invisible things, like database identifiers or normalization.
CJK characters in particular are very problematic, since they must be transliterated differently depending on the locale. Over the years I have received many angry mails from people that were deeply offended by an error in transliteration they saw in an URL or something.
Unihandecode is a fork of Unidecode that tries to address this: