Support MUFI character recommendation

[KrasnayaPloshchad]

The MUFI group published a recommendation for the selection of characters from the Unicode Standard and for characters to be allocated to the Private Use Area (PUA), they are suitable to be implemented in Cormorant fonts. See:
https://folk.uib.no/hnooh/mufi/specs/index.html
Alternatively, you can add more OT features to achieve similar implementations.

[CatharsisFonts]

That's an incredible amount of characters to be added. I won't have time for that anytime soon, sorry. I certainly wouldn't object if someone else wanted to do it, through.