Schema lacking `format` field

[Oran-Dan]

Json Schemas have a very convenient field format to further specify for example the type of string is needed e.g. uri or date-time. For everyone using the Json Schema to validate incoming and outgoing credentials this field is extremely useful, therefore I strongly suggest to add these fields. OBv3 and ELM Json Schema's all have this field included.

I myself used this Schema in this repo in particular schema/verifiable-credential/verifiable-credential-schema.json

Furthermore, in the just mentioned Schema the root id URL seems to be outdated "https://www.w3.org/2022/credentials/v2/verifiable-credential-schema.json".

P.S. I would be happy to contribute the format fields to the mentioned Schema myself in a PR

[msporny]

Yes, please submit a PR @Oran-Dan -- we would really appreciate that!