Add PR to CHANGELOG

Author: adamrtalbot

CHANGELOG.md

@@ -9,7 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Enhancements & fixes
 
-- Update [action-tower-launch](https://github.com/marketplace/actions/action-tower-launch) to v2 which supports more variable handling.
+- [PR #1135](https://github.com/nf-core/rnaseq/pull/1135) - Update [action-tower-launch](https://github.com/marketplace/actions/action-tower-launch) to v2 which supports more variable handling.
 
 ### Software dependencies