Provide merged CJK fonts (like Noto Sans CJK)

[johnnyshields]

Noto provides:

• Noto Sans CJK JP
• Noto Sans CJK KR
• Noto Sans CJK SC
• Noto Sans CJK TC

These fonts contain all CJK glyphs and only override the glyphs affected by Han unification.

Among other reasons for doing this, it will establish consistent rules (e.g. line height) across CJK.

This was mentioned in #388.

[NightFurySL2001]

In #334 question (4), I would believe there is no plans to merge CJK fonts for now.

As you stated, there are technical constraints to combine CJK fonts, so we don’t have plans for an integrated font for now. We are focusing to optimize the font for each script.

[johnnyshields]

It would at least be nice if some standards could be established across CJK. Currently KR and JP have different line heights, different scaling of alpha chars, etc. If IBM doesn't want to provide merged CJK in their distro, that's fine, but it would be nice if the fonts were setup do it's easy to merge manually.