Serve did:web docs? #4

This may be out-of-scope, but one thing I would have liked to see a PLC mirror do is the ability to also serve did:web docs, essentially allowing the PLC mirror to become a drop-in replacement and allow client-side code to use it for both did:plc and did:web. All that needs to happen is Allegedly proxies /did:web:<dw-domain> to https://<dw-domain>/.well-known/did.json.