More generic name

[davux]

It looks like the DID method can be used to resolve DIDs from Fabric, no matter the use case – health passes or other.

Note: Please feel free to close the issue if it is in fact health-specific and I failed to catch it.

I can see a few risks in using a specific name for a generic method:

• People could copy-paste the specification and rename it with their own DID method, resulting in unnecessary fragmentation and lack of interoperability.
• People could think the DID method is not fit for them, and turn to other approaches.

For that reason I suggest the DID method be renamed to reflect its generic property, e.g. did:hf or did:fab. What do you think?