Earth DID or did:earth

[wip-abramson]

When refering to the specification within the text we use two approaches: Earth DID or did:earth.

Personally I prefer did:earth. Wondering if there is a reason for the difference?

If not lets pick one and be consistent throughout.

Earth DID method DIDDoc representation

or

did:earth method DIDDoc representation

[jandrieu]

"did:earth" is preferable and "DIDDoc" should be "DID document".

Just needs a revision.