docs: bump release badge to v2.1.3

Author: Sentinel-Gate

README.md

@@ -12,7 +12,7 @@
   <a href="https://github.com/Sentinel-Gate/Sentinelgate/actions/workflows/ci.yml"><img src="https://img.shields.io/github/actions/workflow/status/Sentinel-Gate/Sentinelgate/ci.yml?style=flat-square&label=CI" alt="CI"></a>
   <a href="LICENSE"><img src="https://img.shields.io/badge/License-AGPL--3.0-blue?style=flat-square" alt="License: AGPL-3.0"></a>
   <a href="https://go.dev"><img src="https://img.shields.io/badge/Go-1.26+-00ADD8?style=flat-square&logo=go&logoColor=white" alt="Go 1.26+"></a>
-  <a href="https://github.com/Sentinel-Gate/Sentinelgate/releases"><img src="https://img.shields.io/badge/Release-v2.1-brightgreen?style=flat-square" alt="Release v2.0"></a>
+  <a href="https://github.com/Sentinel-Gate/Sentinelgate/releases"><img src="https://img.shields.io/badge/Release-v2.1.3-brightgreen?style=flat-square" alt="Release v2.1.3"></a>
 </p>
 
 <p align="center">