VC Registries for CG to establish/manage

At the VCWG Barcelona F2F meeting this week a list of necessary registries
for the VC data model spec was created.  The recommendation is that the CCG
establish and maintain these registries.

The list is here:
https://docs.google.com/presentation/d/1_AKEYKWqaiMIUb6tlo3yVONTl9Z-71H4XfdTtgUF88U/edit#slide=id.g4ff7e4fc63_7_33

-- dan (for the VCWG chairs)