Add Common Serif

[davelab6]

Font Project Git Repo URL:

https://github.com/StefanPeev/Common-Serif

Super short description of the Font Family:

Fork of Libertinus, requested in #12 ; would be good to add these together.

Requirements:

It looks to me like @StefanPeev has got most of the GF requirements (discussed in StefanPeev/Common-Serif#49 - and he asks for help using the template in StefanPeev/Common-Serif#50)

• I think its work collaborating with Stefan on the contributing requirements
• The entire font project is now licensed under the OFL whereas Libertinus has a GPL custom build system (afaik)
• There are "Reserved Font Names" in the upstream Libertinus, currently not mentioned in the OFL license, so I filed Retain RFNs in OFL.txt StefanPeev/Common-Serif#60 to recommend adding them.
• Family name is sadly not unique according to namecheck.fontdata.com, and collides with https://fontsinuse.com/typefaces/219567/abc-common-serif - yet this is not listed on https://abcdinamo.com and fontsinuse says it is "to be released" there. I hope @weiweihuanghuang can comment on the name collision and how to proceed.
• I didn't check if the font supports at least GF Latin Core glyphset but I assume so since Libertinus is pretty big.
• I expect we can collab on the repository repo structure
• The source files are available in the repository
• The project is OFL
• The project is actively maintained