docs: update contributors and add release notes for PR #38 and #39

- Added @Dokhacgiakhoa and @junited31 to Repo Contributors
- Created RELEASE_NOTES.md documenting Vietnamese translations and unreal-engine-cpp-pro skill

README.md

@@ -257,6 +257,8 @@ We officially thank the following contributors for their help in making this rep
 - [Owen Wu](https://github.com/yubing744)
 - [SuperJMN](https://github.com/SuperJMN)
 - [Viktor Ferenczi](https://github.com/viktor-ferenczi)
+- [Đỗ Khắc Gia Khoa](https://github.com/Dokhacgiakhoa) - Vietnamese translations (PR #38)
+- [junited31](https://github.com/junited31) - unreal-engine-cpp-pro skill (PR #39)
 - [krisnasantosa15](https://github.com/krisnasantosa15)
 - [raeef1001](https://github.com/raeef1001)
 - [taksrules](https://github.com/taksrules)

RELEASE_NOTES.md

@@ -0,0 +1,41 @@
+# Release v3.4.0: Internationalization & Game Development
+
+> **Vietnamese translations and Unreal Engine C++ expertise added to the skills collection**
+
+This release brings comprehensive Vietnamese language support for documentation and adds professional Unreal Engine 5.x C++ development guidance, expanding the repository's international reach and game development capabilities.
+
+## 🚀 New Skills
+
+### 🎮 [unreal-engine-cpp-pro](skills/unreal-engine-cpp-pro/)
+
+**Expert-level Unreal Engine 5.x C++ development guide**
+
+Comprehensive guide for developing robust, performant C++ code in Unreal Engine 5. Covers UObject hygiene, garbage collection patterns, performance optimization, and Epic Games' coding standards.
+
+- **UObject & Garbage Collection**: Proper UPROPERTY usage, TStrongObjectPtr patterns, IsValid() checks
+- **Performance Optimization**: Tick management, casting optimization, struct vs class decisions
+- **Naming Conventions**: Strict adherence to Epic Games' coding standards (T, U, A, F, E, I prefixes)
+- **Common Patterns**: Component lookup, interface implementation, async loading with soft references
+- **Example Code**: Complete Actor implementation demonstrating best practices
+
+> **Try it:** `"Help me write a C++ Actor class for Unreal Engine 5"` or `"Show me how to properly use UPROPERTY in Unreal Engine"`
+
+---
+
+## 📦 Improvements
+
+- **Registry Update**: Now tracking 560 skills (was 559).
+- **Internationalization**: Added comprehensive Vietnamese translations for all core documentation
+- **Documentation Structure**: Reorganized Vietnamese translations from `docs/vi/` to `docs/vietnamese/` for consistency
+- **Translation Coverage**: Vietnamese versions now available for README, GETTING_STARTED, CONTRIBUTING, FAQ, SECURITY, QUALITY_BAR, SKILL_ANATOMY, and more
+
+## 👥 Credits
+
+A huge shoutout to our community contributors:
+
+- **@Dokhacgiakhoa** for comprehensive Vietnamese translations (PR #38)
+- **@junited31** for `unreal-engine-cpp-pro` skill (PR #39)
+
+---
+
+_Upgrade now: `git pull origin main` to fetch the latest skills._