[DID Reference] REQUIREMENT: Ability to query a DID Method's resolution capabilities

[mwherman2000]

With the possibility of there being many optional capabilities that are supported by a particular DID Method, we need some way to query, on a DID Method-by-DID Method basis, the list of capabilities that are supported by a particular DID Method. Inspired by this example: #24

This is a simple related specification/protocol I wrote for the NEO Blockchain: https://github.com/neo-project/proposals/blob/master/nep-10.mediawiki

[peacekeeper]

Agreed, seems to be another useful capability. Like #27 I wonder a bit if this is in scope for the DID Resolution spec, or rather an implementation-specific feature that doesn't really need to be standardized. I could imagine it either way, let's discuss.

[mwherman2000]

Closed in favor of #32 Use case 11.