This is a **documentation-only** change. It documents that a ``migrate.sh`` script placed in the Express application directory (the directory containing ``package.json``) is copied into the rock's ``/app`` directory along with the rest of the application, and run by the 12-factor charm before the application starts. The ``expressjs-framework/assets`` extension code, its unit tests, the profile template comments and the spread test changes have been reverted, because no extension code is required for this behaviour. Changes: - Add a "Database migration" section to the Express framework reference page. - Note the ``app`` directory location in the 12-factor how-to. - Remove the inaccurate migrate release note entry. --- - [x] I've followed the [contribution guidelines](https://github.com/canonical/rockcraft/blob/main/CONTRIBUTING.md). - [ ] I've signed the [CLA](http://www.ubuntu.com/legal/contributors/). - [x] I've successfully run `make lint && make test`. - [x] I've added or updated any relevant documentation. - [x] In documents I changed, I [added a meta description](https://canonical-starflow.readthedocs-hosted.com/how-to/add-a-page-meta-description/) if one was missing. - [x] I've updated the relevant release notes.