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

Author: SpraxDev

docs/changes/1.x/1.4.0.md

@@ -17,6 +17,7 @@
 - Allow vAlign and vMerge on Style\Cell to be set to null by [@SpraxDev](https://github.com/SpraxDev) fixing [#2673](https://github.com/PHPOffice/PHPWord/issues/2673) in [#2676](https://github.com/PHPOffice/PHPWord/pull/2676)
 - Reader HTML: Support for differents size units for table by [@Progi1984](https://github.com/Progi1984) fixing [#2384](https://github.com/PHPOffice/PHPWord/issues/2384), [#2701](https://github.com/PHPOffice/PHPWord/issues/2701) in [#2725](https://github.com/PHPOffice/PHPWord/pull/2725)
 - Reader Word2007 : Respect paragraph indent units by [@tugmaks](https://github.com/tugmaks) & [@Progi1984](https://github.com/Progi1984) fixing [#507](https://github.com/PHPOffice/PHPWord/issues/507) in [#2726](https://github.com/PHPOffice/PHPWord/pull/2726)
+- Reader Word2007 : Support Header elements within Title elements by [@SpraxDev](https://github.com/SpraxDev) fixing [#2616](https://github.com/PHPOffice/PHPWord/issues/2616), [#2426](https://github.com/PHPOffice/PHPWord/issues/2426) in [#2674](https://github.com/PHPOffice/PHPWord/pull/2674)
 
 ### Miscellaneous