Clarify which deterministic scheme is being used

[hoxxep]

Hello, judging by the code¹ this repo follows the RFC 8949 4.2.1 spec for map key ordering (bytewise lexicographic). It's a little ambiguous, as the spec also includes the 4.2.3 backwards compatible scheme (length-first).

I've run into the same confusion with ciborium recently, and have been writing a PR enarx/ciborium#143 there to make the difference between the two flavours more obvious. I noticed cbor.me used dCBOR but didn't make it obvious which canonicalization scheme was being used.

Perhaps it would be helpful if it could be made more clear in the README or docs somewhere?

Cheers,
Liam