Add language on which version(s) of JSON Schema are supported

[decentralgabe]

Which version(s) of JSON Schema are supported?
Should it be left up to implementers?
Should we call out specific versions?

[decentralgabe]

Call out the latest versions:

• https://datatracker.ietf.org/doc/html/draft-bhutton-json-schema-01
• https://datatracker.ietf.org/doc/html/draft-bhutton-json-schema-validation-01
• https://datatracker.ietf.org/doc/html/draft-bhutton-relative-json-pointer-00

[decentralgabe]

Add a section to support specific versions of JSON Schema, can be able to say I just support draft 7, etc...

• Multiple types?
• Another attr?

[decentralgabe]

Handled in #132