JSON schema for MLayer objects

[ryanmwhitephd]

JSON schema will be useful to incorporate MLayer scales, aspect, etc... into registry type systems or NoSQL database systems.

[ryanmwhitephd]

See the type registries related to FAIR Digital Object development.
https://fc4e-t4-3.github.io/
https://typeregistry.lab.pidconsortium.net/

and specifically the MeasurementUnit type:
https://typeregistry.lab.pidconsortium.net/#objects/21.T11969/db25df9ee59dad13a5c9