[webauthn] add feature detection blurb... (#1208)

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

== add feature detection blurb... ==
..pointing  back to credman's [section 7.1. Website Authors](https://www.w3.org/TR/credential-management-1/#implementation-authors), which briefly & explicitly explains that trying to use `if (!navigator.credentials) ...` is suboptimal for feature detection, rather `if (!window.PublicKeyCredential) ...` ought be used.  [[the examples in webauthn](https://w3c.github.io/webauthn/#sample-authentication) already use  the latter as feature detection, so they are already good]


Please view or discuss this issue at https://github.com/w3c/webauthn/issues/1208 using your GitHub account

Received on Monday, 6 May 2019 21:35:23 UTC