chore: update CHANGELOG

Author: igordejanovic

CHANGELOG.md

@@ -21,6 +21,10 @@ backward incompatible changes will start to apply when the projects goes 1.0
 ### Fixed
 - Fix `to_str` failure when calculating the number of solutions in the context
   of optional match ([#147]). Thanks @LVrecar for the report and fix.
+  
+### Changed
+- Drop support for Python 3.6/3.7
+- Migrated to pyproject.toml and ruff
 
 [#147]: https://github.com/igordejanovic/parglare/issues/147