Add did:tdw (Trusted Digital Web / Web 7.0)

[mwherman2000]

----- DID METHOD REGISTRATION FORM: DELETE EVERYTHING ABOVE THIS LINE ------

DID Method Registration

As a DID method registrant, I have ensured that my DID method registration complies with the following statements:

• [ x] The DID Method specification defines the DID Method Syntax.
• [ x] The DID Method specification defines the Create, Read, Update, and Deactivate DID Method Operations.
• [ x] The DID Method specification contains a Security Considerations section.
• [ x] The DID Method specification contains a Privacy Considerations section.
• [ x] The JSON file I am submitting has passed all automated validation tests below.
• [ x] The JSON file contains a contactEmail address [OPTIONAL].
• [ x] The JSON file contains a verifiableDataRegistry entry [OPTIONAL].

[mwherman2000]

In his last Zoom call, @swcurran and I agreed that, to avoid confusion for the next several months, Web 7.0/Trusted Digital Web would postpone using did:tdw until Nov. 1, 2025.

UPDATE: Related, I've proposed a future solution to the "attestation of unique DID Method names" problem here: #597