Moves changelog link generation from inline heading format ## [1.1.0](https://...) - date to reference-style definitions at the bottom of the file ## [1.1.0] - date ... [Unreleased]: https://.../src/branch/main [1.1.0]: https://.../releases/tag/v1.1.0 This keeps headings plain, which simplifies changelog parsing (the awk pattern in publish/action.yml now matches without special-casing the inline URL), and follows the canonical Keep a Changelog style.