This is A5's starting point for new Drupal 10 projects based on Pantheon's D10 upstream.
Unlike with earlier Pantheon upstreams, files such as Drupal Core that you are unlikely to adjust while building sites are not in the main branch of the repository. Instead, they are referenced as dependencies that are installed by Composer.
For more information and detailed installation guides, please visit the Integrated Composer Pantheon documentation: https://pantheon.io/docs/integrated-composer