Editorial guidelines for choosing fonts in non-Western scripts

[ZeLonewolf]

Originally posted by @1ec5 in #801 (comment)

Not sure if it should go here or in CONTRIBUTING.md, but we could document some editorial guidelines to aid in choosing fonts in non-Western writing systems. For example, once we get around to implementing custom CJK fonts, either on the server side via a fontstack or (preferably) on the client side via standard Web fonts, we’d want to pair Western regular sans-serif with gothic and Western regular serif with Ming, and Western italic sans-serif with regular, based on what Western and CJK texts do in analogous situations.

That said, one of the outgrowths of this PR may end up being a separate project specifically about fonts, where we’d naturally explore and elaborate on these ideas.