docs(changelog): Add note about supporting Header elements within Title

Author: SpraxDev

docs/changes/1.x/1.4.0.md

@@ -9,6 +9,7 @@
 ### Bug fixes
 
 - Writer ODText: Support for images inside a textRun by [@Progi1984](https://github.com/Progi1984) fixing [#2240](https://github.com/PHPOffice/PHPWord/issues/2240) in [#2668](https://github.com/PHPOffice/PHPWord/pull/2668)
+- Support Header elements within Title elements by [@SpraxDev](https://github.com/SpraxDev) in [#2674](https://github.com/PHPOffice/PHPWord/pull/2674)
 
 ### Miscellaneous