Remove the quick-start script from the project template, in favor of compatibility with core's quick start

The prototype had its own quick-start command, but now that we have our own installation profile for Drupal CMS, we don't really need it. All we need is a one-line core patch to allow core's built-in quick-start command to automatically select distributions. So folks who don't want to use DDEV can do this:

composer create-project ...
cd project-dir/web
php core/scripts/drupal quick-start

And it will spin up Drupal CMS in a SQLite database. For a "real" project, you'd probably want to use DDEV; this MR doesn't affect the existing ddev quick-start script.