udpate changelog

Author: spipu

CHANGELOG.md

@@ -8,6 +8,7 @@ All notable changes to this project will be documented in this file.
   * update doc about Security service
   * fix security issue on css background-image validation - thanks to Aleksey Solovev and Nikita Sveshnikov ([Positive Technologies](https://www.ptsecurity.com))
   * fix security issue on image src validation - thanks to Aleksey Solovev ([Positive Technologies](https://www.ptsecurity.com))
+  * fix on Index creation if no bookmark - thanks to @rhulha
 
 ## [5.3.1](https://github.com/spipu/html2pdf/compare/v5.3.0...v5.3.1) - 2025-02-26