Update README.md

Added reference architecture

Author: ocisec-coder

cloud-infrastructure/infrastructure-security/bastion/README.md

@@ -2,7 +2,7 @@
 
 Oracle Cloud Infrastructure Bastion provides restricted and time-limited access to target resources that don't have public endpoints.
 
-Reviewed: 18.11.2024
+Reviewed: 16.10.2025
 
 # Table of Contents
 
@@ -25,6 +25,9 @@ Reviewed: 18.11.2024
 - [OCI Bastion Demo Video](https://www.youtube.com/watch?v=MkM_fJbFjJg)
     - This is the demo video of the OCI bastion service
 
+- [OCI Bastion Reference Architecture](https://docs.oracle.com/en/solutions/use-bastion-service/index.html#GUID-E30EE335-0EFD-4212-BD47-171203160723)
+    - This is the reference architecture for OCI bastion service
+ 
 # License
 
 Copyright (c) 2025 Oracle and/or its affiliates.