link issue and pr number to changelog entry

Author: ffakenz

CHANGELOG.md

@@ -40,6 +40,7 @@ changes.
 - Label threads, queues and vars.
 
 - **BREAKING** Enable handling client recover in all head states.
+  - See [Issue #1812](https://github.com/cardano-scaling/hydra/issues/1812) and [PR #2217](https://github.com/cardano-scaling/hydra/pull/2217).
 
 ## [0.22.4] - 2025-08-05