[w3c/webauthn] 5c3054: Spelling and grammar corrections (#815)

  Branch: refs/heads/master
  Home:   https://github.com/w3c/webauthn
  Commit: 5c3054f1f0e2a3eeb8a4f24b39032a5a239920b2
      https://github.com/w3c/webauthn/commit/5c3054f1f0e2a3eeb8a4f24b39032a5a239920b2
  Author: Mike Jones <Michael.Jones@microsoft.com>
  Date:   2018-02-22 (Thu, 22 Feb 2018)

  Changed paths:
    M index.bs

  Log Message:
  -----------
  Spelling and grammar corrections (#815)

* Spelling and grammar corrections

* Fix a few more a/an errors

* Apply <code>...</code> as suggested