No longer claim that U2F workflow as sole authentication method is a bad idea
It is follow up to https://gitlab.com/gitlab-org/gitlab-ce/issues/57446 and https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/25047#note_140801257
https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/user/profile/account/two_factor_authentication.md displayed at https://gitlab.com/help/user/profile/account/two_factor_authentication currently has "we strongly recommend that you set up both methods of two-factor authentication, so you can still access your account from other browsers."
It is based on outdated situation when solely Google Chrome supported U2F.
I recommend to withdraw this recommendations together with word "only" in "U2F workflow is only supported by Google Chrome, Opera and Firefox at this point".
I can make PR after confirmation that whoever is responsible for recommendations at Gitlab is not against that change.