add pr number to changelog

Author: labrenbe

CHANGELOG.md

@@ -6,9 +6,9 @@ All notable changes to this project will be documented in this file.
 
 ### Fixed
 
-- Fix a bug where changes to ConfigMaps that are referenced in the Druid spec didn't trigger a reconciliation ([#]).
+- Fix a bug where changes to ConfigMaps that are referenced in the Druid spec didn't trigger a reconciliation ([#704]).
 
-[#]: https://github.com/stackabletech/druid-operator/pull/
+[#704]: https://github.com/stackabletech/druid-operator/pull/704
 
 ## [25.3.0] - 2025-03-21