docs(architecture): add rationale and improve project documentation

Author: bsayli

README.md

@@ -556,12 +556,27 @@ The provided parent configuration includes a tested default, but consumers may o
 
 ## References
 
+### Project Documentation
+
+- **Rationale**  
+  [Why OpenAPI Generics Exists](./docs/architecture/rationale.md) — Explains the architectural motivation, engineering trade-offs, and ecosystem constraints behind the project.
+
 - **Adoption Guide (GitHub Pages)**  
   [Spring Boot OpenAPI Generics — Adoption Guide](https://blueprint-platform.github.io/openapi-generics/)
 
+### Articles
+
 - **Medium Article**  
   [We Made OpenAPI Generator Think in Generics](https://medium.com/@baris.sayli/type-safe-generic-api-responses-with-spring-boot-3-4-openapi-generator-and-custom-templates-ccd93405fb04)
 
+### Standards & Specifications
+
+- **OpenAPI Specification 3.2.0**  
+  https://spec.openapis.org/oas/v3.2.0.html
+
+- **JSON Schema Draft 2020-12**  
+  https://json-schema.org/draft/2020-12
+
 - **RFC 9457**  
   [Problem Details for HTTP APIs](https://www.rfc-editor.org/rfc/rfc9457)
 

docs/architecture/architecture.md

@@ -161,13 +161,13 @@ Supported capabilities:
 
 ## Module Map
 
-| Module | Responsibility |
-|----------|----------------|
-| [`openapi-generics-contract`](../../README.md) | Shared contracts and platform types |
-| [`openapi-generics-server-starter`](../../openapi-generics-server-starter/README.md) | Spring Boot projection pipeline |
-| [`openapi-generics-java-codegen`](../../openapi-generics-java-codegen/README.md) | Contract-aware OpenAPI Generator extension |
+| Module                                                                                         | Responsibility |
+|------------------------------------------------------------------------------------------------|----------------|
+| [`openapi-generics-contract`](../../openapi-generics-contract/README.md)                                                    | Shared contracts and platform types |
+| [`openapi-generics-server-starter`](../../openapi-generics-server-starter/README.md)           | Spring Boot projection pipeline |
+| [`openapi-generics-java-codegen`](../../openapi-generics-java-codegen/README.md)               | Contract-aware OpenAPI Generator extension |
 | [`openapi-generics-java-codegen-parent`](../../openapi-generics-java-codegen-parent/README.md) | Generator orchestration and template lifecycle |
-| [`openapi-generics-platform-bom`](../../openapi-generics-platform-bom/README.md) | Dependency alignment |
+| [`openapi-generics-platform-bom`](../../openapi-generics-platform-bom/README.md)               | Dependency alignment |
 
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