All notable changes specific to pantheon-upstreams/drupal-project are noted here.
- Add changelog to track Pantheon-specific changes to pantheon-upstreams/pantheon-project. (#10)
- Two repositories for release management. Pull requests accepted at https://github.com/pantheon-systems/drupal-project and releases located at https://github.com/pantheon-upstreams/drupal-project. (#4,#5)
- Allow site-level customization of Drush version. (#5)
- Allow sites to downgrade to Drupal 8.8. (#6)
- Use optimized autoloader in Test and Live, but not Dev or Multidev (#8)
- Remove install check and MariaDB minimum version patches. (#3)
The associated milestone in GitHub provides detailed information about all changes in this update.