docs: update the architectural diagram in header.md in root module

Author: Rahul-4480

.header.md

@@ -6,7 +6,7 @@ This Terraform module automates the deployment of the Atlantis server on an ECS
 
 ### Architectural Diagram
 
-![atlantis](https://github.com/user-attachments/assets/0252b4a9-38e3-4e8d-9212-fcfc091001a4)
+![Atlantis](https://github.com/user-attachments/assets/f438c7af-9aee-415e-93a4-a1bb5a9f6c0e)
 
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