You might be interested in heirloom troff. Supports UTF-8 so French might be fine, but I'm not sure about Chinese characters.

https://n-t-roff.github.io/heirloom/doctools.html

The page below might be of some use - seems like some work needed to get groff (GNU troff) to use Chinese characters.

https://kleshwong.com/blog/post/composing-pdf-on-linux-happi...