Make a Beta release (Latin only?)

[davelab6]

Now that we've moved on from Latin to Greek and Cyrillic it would be good to make a release on https://github.com/typenetwork/amstelvar/releases as a "beta" (with family metadata as eg Amstelvar Beta 20201006 if we did it today) with a nice ZIP package for people to download - I still see Amstelvar Alpha being used in a lot of VF demos and it should be obvious to people that they should not use that any more.

[dberlow]

Release an Amstelvar Roman and italic beta with latin complete, Greek and Cyrillic registered glyph completion by nov. 1. Greek and Cyrillic parametric by dec.1 Full hinting, features and docs Jan.21, 2021?