Support CJK characters

[deeplow]

We need to add CJK fonts for support Chinese, Japanese, and Korean languages. We can use for example the package font-noto-cjk-extra.

Before	After

[OctopusET]

#460 (comment)
Like I commented here, there's some characters still not able to render. But only some very old articles would be the cases.

I think some day fonts should be added manually (and safely).

[OctopusET]

I have to test but font-noto-cjk-extra might be not necessary for just showing characters. Some fonts like 'bold' might be render different, but if you think it would increase image size a lot font-noto-cjk would be enough

[OctopusET]

I tested with this file.
This file contains the following fonts: "Noto Sans CJK KR *", "IBM Plex Sans KR *", "Noto Serif CJK KR *".

Original	font-noto-cjk	font-noto-cjk-extra

I think font-noto-cjk would be sufficient. Although font-noto-cjk-extra can render much more fonts, but that's because those glyph (e.g. Noto Sans CJK Light) are also the noto fonts. For example, even IBM Plex Sans uses other glyph like 'IBM Plex Sans light' that Noto fonts can't render.

[deeplow]

Thanks for investigating. Looks like font-noto-cjk will have to cut it for now. font-noto-cjk-extra would add an extra 200MB of downloaded packages.