text: Title: set jwt_cookie on signup
  Body: First of all, thank you for the lib.
  In my case, I need to set the `jwt_cookie` right after the signup. I've already read the docs and the issues too, so I know about the `get_token` decorator but I need a solution to be able to set the cookie.
  
  is there any way to `authenticate` the user in a func, so the necessary tasks get done automatically? (including `jwt_cookie setup`)
  if no, is it alright to set up the cookie manually?