Add a non-English language documentation category on the website.

[Zimmi48]

I'm thinking that the https://coq.inria.fr/documentation page could benefit from a section listing all the available documentation in other languages than English.

We could list:

• the French and Chinese translation of the Coq'Art
• the Chinese translation of SF (cc @liyishuai)
• the book in Japanese by Manabu Hagiwara and @affeldt
• the video lectures of @ybertot in French that are already mentioned on this page

What else?

[gares]

There are some volumes about ssr in japanese dunno if they are online CC @pi8027

[Zimmi48]

Different from "the book in Japanese by Manabu Hagiwara and @affeldt" (www.morikita.co.jp/books/book/3287)?

[affeldt-aist]

This is different. I think that @gares is referring to printed material written mostly by @pi8027 that he has been distributing domestically. But I don't think you can find them online.