chore: update CHANGELOG for version 1.1.0 with Dart 3.0+ support and new features

Author: Chinmay-KB

CHANGELOG.md

@@ -1,3 +1,15 @@
+## [1.1.0] - 2025
+
+* Updated to Dart 3.0+ with modern SDK constraints (>=3.0.0 <4.0.0)
+* Added `unescapeRegExp()` method to unescape regex strings
+* Code refactoring and improved maintainability
+* Updated dependencies to latest compatible versions
+
+## [1.0.0] - 2021
+
+* First stable release
+* All string manipulation features from prerelease now stable
+
 ## [0.0.1-prerelease] - 04/01/2021
 
 * Added functionalities either missing from String class.