[webauthn] more fully delineate "privacy ca", "attestation ca", "anonymization ca" (#1422)

equalsJeffH has just created a new issue for https://github.com/w3c/webauthn:

== more fully delineate "privacy ca", "attestation ca", "anonymization ca"  ==
the "privacy ca", "attestation ca", "anonymization ca" terms appear in the spec in various places and the Note in [14.4.1. Attestation Privacy](https://w3c.github.io/webauthn/#sctn-attestation-privacy) attempts to tease them apart, but could do a better job.  Am imagining appending a bulleted list summarizing each's particular characteristics, or re-writing the Note to more clearly delineate between them.

Please view or discuss this issue at https://github.com/w3c/webauthn/issues/1422 using your GitHub account