RELEASE.md

Release

1. Update documentation (check update, upgrade instructions)
2. Update installation section in administrator documentation (supported extensions)
3. Update dependencies in composer.json
4. Update changelog
   
   1. Create changelog file for release (e.g. Changelog/9.0.0.rst)
   2. Update Changelog/Index.rst
5. Update version in ext_emconf.php
6. Update version in documentation/Settings.cfg
7. Commit release
8. Test
9. Create tag for release
10. Push to github
11. Check at packagist.org
12. Upload to TER