[Feature Request] Redirect to auth provider immediately

[TheOneValen]

I propose a new (optional) auth config option to configure docspell to redirect directly to the auth provider when the user is not logged in, e.g.

  auth {
  default-provider="keycloak"
}

Immediatly redirects the user to the auth configured under openid with the display name "keycloak". Leaving this value empty or on "local" would display the current login screen and the buttons underneath.

[eikek]

As a workaround for now one could bookmark the link of this button, maybe (instead of the normal page)