App Manager v1.124.15 release notes (#3181)

* App Manager v1.124.15 release notes

* Update rn-app-manager.md

* change new feature to improvement

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Co-authored-by: replicated-ci-kots <91219917+replicated-ci-kots@users.noreply.github.com>
Co-authored-by: Salah Al Saleh <sg.alsaleh@gmail.com>
Co-authored-by: Paige Calvert <paige@replicated.com>

Author: 4 people

docs/release-notes/rn-app-manager.md

@@ -18,13 +18,22 @@ The following table lists the versions of Kubernetes that are compatible with ea
 
 <!--RELEASE_NOTES_PLACEHOLDER-->
 
+## 1.124.15
+
+Released on April 14, 2025
+
+Support for Kubernetes: 1.29, 1.30, and 1.31
+
+### Improvements {#improvements-1-124-15}
+* Improvements for multi-node Embedded Cluster.
+
 ## 1.124.14
 
 Released on April 9, 2025
 
 Support for Kubernetes: 1.29, 1.30, and 1.31
 
-### New Features {#new-features-1-124-14}
+### Improvements {#improvements-1-124-14}
 * Improvements for multi-node Embedded Cluster.
 
 ## 1.124.13