docs(README): add automated validation feature description

- Describe the new robust & automated validation feature
- Explain how it eliminates runtime errors and reduces repetitive validation code
- Highlight the benefits for data model consistency and API resilience

Author: fulleni

README.md

@@ -65,6 +65,12 @@ The data API is equipped with powerful querying capabilities, enabling rich, hig
 - **High-Performance Pagination:** Utilizes efficient cursor-based pagination to handle massive datasets gracefully, perfect for infinite-scrolling feeds.
 > **Your Advantage:** Empower your mobile and web clients with powerful data discovery features right out of the box, without needing to write any extra backend logic.
 
+---
+
+### 🛡️ Robust & Automated Validation
+The API automatically validates the structure of all incoming data, ensuring that every request is well-formed before it's processed. This built-in mechanism catches missing fields, incorrect data types, and invalid enum values at the gateway, providing clear, immediate feedback to the client.
+> **Your Advantage:** This eliminates an entire class of runtime errors and saves you from writing tedious, repetitive validation code. Your data models remain consistent and your API stays resilient against malformed requests.
+
 </details>
 
 <details>