Add prompt to get the token from the user in script and notebook with instruction

[danieleguido]

from impresso import api
api.login()

Click on the provided link to access the login page: https://impresso-project.ch/datalab/login
 - Log in with your credentials on the browser page.
 - Once logged in, you will be redirected to a page. Don't close the browser yet!
 - The browser page will contain a token. Copy the token.
 - Return to the terminal (or Jupyterlab notebook) where the script is running.
Please paste here the token you've received: