Add typeface and type styles for CJK characters in SW4

[gissoo]

@rlskoeser Some context based on our final design decisions:

• we are keeping the IBM Plex Serif for latin characters and Noto Serif for non-latin characters. Here you can see what it would look like for Nick's and Gian's article and here you can see what it would look like for Aliz's piece

Note: to make them fit better I have reduced the Noto Serif by 2px, i.e. it is always 2px smaller than IBM Plex Serif. On desktop it's 18px and on mobile it's 16px.

I think this is the source where I got the font

[gwijthoff]

Resolved in #333