Update JSON Schema to YAML and OAS3.0

[OR13]

RESOLVED: The trace vocab will use OAS3.0 Schemas represented in YAML, instead of JSON Schema represented in JSON.

[TallTed]

per #186

[tobek]

I'm sure I'm missing some context here, but does this proposal supercede #184 and #185, or will JSON Schemas still be maintained (and JSON-LD contexts still generated from them)?

For our (@SertoID) work we plan to keep using JSON Schema for validation and VC credentialSchema field purposes, and I'm curious what other projects are planning here.

[OR13]

@tobek I think for this repo, we would switch to yaml, but the underlying library would continue to support YAML or JSON.... I suspect we can even make the $comment vs $linkedData a backward compatible feature of the tool.

similar to how OAS3.0 works today, I think constraining data shape with YAML or JSON schemas will be part of the next vc data model, and hopefully better documented in the next version.

[OR13]

but to be clear, we are hoping to switch to yaml representation of JSON schema here, to make interactions with OAS3.0 easier.

[OR13]

Upstream implementation updated to support this: transmute-industries/verifiable-data#118

[OR13]

This is done, I am closing.