Update readme file

README.md

@@ -9,6 +9,39 @@ To understand the initial state of the project, please refer to the [previous RE
 ### API Docs from V1 application version
 https://greenlight.tarralva.com/swagger/index.html
 
+### Diagram
+```mermaid
+graph LR
+  subgraph ModularMonolith
+    subgraph AuthModule
+      subgraph DomainLayer
+        D1[Entities]
+        D2[Value Objects]
+      end
+      subgraph ApplicationLayer
+        A1[Use Cases]
+      end
+      subgraph InfrastructureLayer
+        I1[Repositories]
+        I2[REST API External Services]
+        I3[GRPC Internal Service]
+      end
+    end
+    subgraph Legacy Module
+      subgraph RestServer
+        RS1[Controllers]
+        RS2[Handlers]
+        subgraph Middleware
+          RS3[Auth GRPC Client]
+        end
+      end
+      subgraph Data Models
+      end
+    end
+  end
+```
+The diagram represents the initial phase of the refactor process, focusing on separating the auth module from the existing codebase and applying a clean architecture to enhance its maintainability to each new module. The main objective is to isolate the auth module's functionality and ensure that other modules access user-related information and authentication through the internal GRPC auth service.
+
 ### TODO
 - [x] Implement a modular monolith architecture style
 - [ ] Refactor initial implementation into separate modules