chore: add changelog

Signed-off-by: Bart Jaskulski <bartek.jaskulski@wpdesk.net>

CHANGELOG.md

+# WP Migrations Changelog
+
+## [1.0.2] - 12-12-2022
+### Fixed
+- Migration no longer iterates over all registered entries. Install only newest versions.
+
+## [1.0.1] - 15-06-2022
+### Fixed
+- Improved saving log entries to database.
+
+## [1.0.0] - 14-06-2022
+### Added
+- Initial release.