A more user-friendly entity reference list field widget for Drupal 8.
Development of this project is moved to Drupal.org: https://www.drupal.org/project/bert
Use the scripts/upgrade-to-bert.sh script to help with your migration.
You also have to move any custom plugins from the Plugin/EntityReferenceListFormatter and Plugin/EntityReferenceLabelFormatter directories to a Plugin/bert/EntityReferenceListFormatter or Plugin/bert/EntityReferenceLabelFormatter directory.