[w3c/webauthn] be0b62: Update index.bs

  Branch: refs/heads/acz
  Home:   https://github.com/w3c/webauthn
  Commit: be0b621bf02306492bbad01d1f82060712f64fc9
      https://github.com/w3c/webauthn/commit/be0b621bf02306492bbad01d1f82060712f64fc9
  Author: Alexei Czeskis <alexei@czeskis.com>
  Date:   2017-08-01 (Tue, 01 Aug 2017)

  Changed paths:
    M index.bs

  Log Message:
  -----------
  Update index.bs