Signing EarthState Artifact Using DIDKit e.g. hydroelec.project1.json

[wip-abramson]

I tried to sign this earthstate artifact - https://github.com/LegReq/artifacts/blob/main/rec/hydroelec.project1.json

Couple of things I noticed.

• It isn't currently conformant
  -- Missing the credentialSubject & issuanceDate fields
  -- I think type should be ["VerifiableCredential", "REC2022/Proposal"]
  -- I also wondered if all the extra fields e.g. geographicLocation should be within a credentialSubject object

• To sign with the didkit-cli we have to have defined the contexts that describe the schema of the VC.
  -- Can do this directly in the context e.g. ["https://www.w3.org/2018/credentials/v1",{"givenName": "schema:givenName"}],
  -- Or with a resolvable url e.g. https://www.w3.org/2018/credentials/examples/v1