Prep release

Author: dvdoug

CHANGELOG.md

@@ -1,6 +1,10 @@
 # Changelog
 
 ## [3.x - Unreleased] - 2023-xx-xx
+
+## [3.12.0] - 2023-07-30
+### Changed
+- Improved efficiency in packing
 ### Removed
 - Support for PHP 7.1, 7.2 and 7.3
 
@@ -495,8 +499,9 @@ Initial release
  - Experimental code to get a feel for how calculations can best be implemented
  - Only works if all items fit into a single box (so not production ready at all)
 
-[3.x - Unreleased]: https://github.com/dvdoug/BoxPacker/compare/3.11.0...3.x
+[3.x - Unreleased]: https://github.com/dvdoug/BoxPacker/compare/3.12.0...3.x
 
+[3.12.0]: https://github.com/dvdoug/BoxPacker/compare/3.11.0...3.12.0
 [3.11.0]: https://github.com/dvdoug/BoxPacker/compare/3.10.0...3.11.0
 [3.10.0]: https://github.com/dvdoug/BoxPacker/compare/3.9.4...3.10.0
 [3.9.4]: https://github.com/dvdoug/BoxPacker/compare/3.9.3...3.9.4