feat: Add comprehensive documentation suite and reorganize project structure

- Created complete documentation in docs/ directory
- Added PROJECT_OVERVIEW.md with feature highlights and getting started guide
- Added ARCHITECTURE.md with system design and technical details
- Added SECURITY.md with comprehensive security implementation guide
- Added DEVELOPMENT.md with development workflows and best practices
- Added DEPLOYMENT.md with production deployment instructions
- Added API.md with complete REST API documentation
- Added CONTRIBUTING.md with contribution guidelines
- Added CHANGELOG.md with version history and migration notes
- Reorganized all documentation files into docs/ directory for better organization
- Updated README.md with proper documentation links and quick navigation
- Enhanced project structure with professional documentation standards

f_scripts/shared/flagicon/flags/1x1/ng.svg

@@ -0,0 +1,6 @@
+<svg xmlns="http://www.w3.org/2000/svg" height="512" width="512" version="1" viewBox="0 0 512 512">
+  <g fill-rule="evenodd" stroke-width="1pt">
+    <path fill="#fff" d="M0 0h511.98v511.984H0z"/>
+    <path fill="#36a100" d="M341.32 0h170.66v511.984H341.32zM0 0h170.66v511.984H0z"/>
+  </g>
+</svg>