Upgrading Adminimal Theme to Drupal 11 Unstable Release

Although Adminimal Theme doesn't have a stable Drupal 11 release yet, you can use Composer to fetch a development version that works with Drupal 11. By modifying your composer.json file to point to the development branch and running composer update, you can start using adminimal_theme on Drupal 11 today, with the understanding that it's unstable pre-release code