The update which enables Chinese language support is now live. Please do not forget that you can change the language of the game in the Language tab of the Properties: right-click the game in the Library section of the Steam client and select Properties. In the Language tab choose the language.
Please be aware that different language versions of the game do not share the save files, as well we do not guarantee compatibility of the save files among the three versions of the games, because may lead to unexpected issues. Therefore we strongly advise to avoid performing such actions.
Source: Steam Community (opens in a new tab)