Pick a library for front-end verification of credential request

[dontcallmedom]

To facilitate deployment of the various versions of the Practical WebAuthn demo, we plan to provide an option that doesn't need back-end verifications; there are a few libraries out there that can fulfill that need. We should list them and understand their pros & cons.

We also will want to make abundantly clear that front-end verification is NOT something that should be done in production code.

[nicksteele]

Two libraries that handle front-end verification that come to top of mind for me are:
Shane Weeden's FIDO Viewer
J.C. Jones's webauthn.bin.coffee

If anyone knows others please feel free to add them!