Update CHANGELOG

Author: codeaholicguy

CHANGELOG.md

@@ -5,6 +5,28 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.5.0] - 2025-01-15
+
+### Added
+- **Antigravity Support** - Added support for Google Antigravity (Gemini CLI) as a new AI development environment
+- **New Slash Command** - `/simplify-implementation` for analyzing and simplifying existing implementations
+  - Reduce complexity and improve maintainability
+  - Structured approach with readability principles
+  - Prioritized action plans with risk assessment
+  - Scalability recommendations
+
+### Changed
+- **Dynamic TOML Generation** - Refactored TemplateManager to dynamically generate `.toml` files from `.md` files at runtime
+  - Added YAML frontmatter support for storing command descriptions in Markdown files
+  - Uses `gray-matter` library for frontmatter parsing
+  - Eliminated duplication between `.toml` and `.md` template files
+  - Removed all static `.toml` files from the templates directory
+
+### Technical Improvements
+- Updated TypeScript configuration
+- Improved test coverage for TemplateManager
+- Updated documentation for supported agents
+
 ## [0.4.2] - 2025-11-05
 
 - Fixed Gemini CLI integration https://github.com/codeaholicguy/ai-devkit/issues/3