* - base_path: The base URL path of the Drupal installation. Will usually be
* "/" unless you have installed Drupal in a sub-directory.
* - is_front: A flag indicating if the current page is the front page.
* - logged_in: A flag indicating if the user is registered and signed in.
* - is_admin: A flag indicating if the user has permission to access
* administration pages.
*
* Site identity:
* - front_page: The URL of the front page. Use this instead of base_path when
* linking to the front page. This includes the language domain or prefix.
https://stackoverflow.com/questions/41182521/get-base-path-in-twig-file-drupal-8