Update imdg-clients.txt

Add .Net Client 5.3.1

Author: emreyigit

imdg-clients.txt

@@ -965,6 +965,15 @@ ReleaseNotes:
 ---
 ========== .NET/CSharp Client
 ---
+Version: 5.3.1
+Date: 10/04/2023
+Download: https://www.nuget.org/api/v2/package/Hazelcast.Net/5.3.1
+Download_Size: 2 MB
+Github: https://github.com/hazelcast/hazelcast-csharp-client/tree/v5.3.1
+Docs: http://hazelcast.github.io/hazelcast-csharp-client/5.3.1/doc/index.html
+APIDocs: http://hazelcast.github.io/hazelcast-csharp-client/5.3.1/api/index.html
+ReleaseNotes: https://github.com/hazelcast/hazelcast-csharp-client/releases/tag/v5.3.1
+---
 Version: 5.3.0
 Date: 06/23/2023
 Download: https://www.nuget.org/api/v2/package/Hazelcast.Net/5.3.0