Update studio docs for v1.2.1 release

docs/en/studio/release-notes.md

@@ -2,6 +2,15 @@
 
 This document contains **brief release notes** for each ABP Studio release. Release notes only include **major features** and **visible enhancements**. Therefore, they don't include all the development done in the related version. 
 
+## 1.2.1 (2025-08-14)
+
+* Upgraded template dependencies for ABP Framework and LeptonX. (targeting ABP `9.3.1`)
+* Migrated templates to standalone structure for Angular UI.
+* Allowed relating tools with Kubernetes Services (allows to browse tools dashboard those are running in k8s).
+* Made several enhancements for Solution Runner.
+* Added test projects to **Application (Single Layer)** template (optional).
+
+
 ## 1.1.2 (2025-07-31)
 
 * Upgraded template dependencies for ABP Framework and LeptonX. (targeting ABP `9.2.3`)

docs/en/studio/version-mapping.md

@@ -4,6 +4,7 @@ This document provides a general overview of the relationship between various ve
 
 | **ABP Studio Version** | **ABP Version of Startup Template**           |
 |------------------------|---------------------------|
+| 1.2.1                  | 9.3.1                     |
 | 1.1.2                  | 9.2.3                     |
 | 1.1.0 - 1.1.1          | 9.2.2                     |
 | 1.0.2                  | 9.2.1                     |