chore: changelog update

changelog.txt

 # Changelog
 
-## [3.3.0] - 2025-04-XX
+## [4.0.0] - 2025-04-XX
 ### Added
 - ToggleField class, extends CheckboxField for toggle button functionality.
+### Changed
+- Declared nullable parameter types (e.g. `?string`, `?Renderer`) to fix PHP 8.4 deprecation warnings about implicitly nullable parameters.
+### Removed
+- Support for PHP < 7.1.
+
 
 ## [3.2.1] - 2024-10-30
 ### Changed