feat: add 33 skills from vudovn/antigravity-kit

- Added: api-patterns, app-builder, architecture, bash-linux, behavioral-modes,
  clean-code, code-review-checklist, database-design, deployment-procedures,
  docker-expert, documentation-templates, game-development, geo-fundamentals,
  i18n-localization, lint-and-validate, mobile-design, nestjs-expert,
  nextjs-best-practices, nodejs-best-practices, parallel-agents,
  performance-profiling, plan-writing, powershell-windows, prisma-expert,
  python-patterns, react-patterns, red-team-tactics, seo-fundamentals,
  server-management, tailwind-patterns, tdd-workflow, typescript-expert,
  vulnerability-scanner
- Updated README: skill count 179 → 223
- Added credit for vudovn/antigravity-kit (MIT License)

Source: https://github.com/vudovn/antigravity-kit

skills/api-patterns/documentation.md

@@ -0,0 +1,26 @@
+# API Documentation Principles
+
+> Good docs = happy developers = API adoption.
+
+## OpenAPI/Swagger Essentials
+
+```
+Include:
+├── All endpoints with examples
+├── Request/response schemas
+├── Authentication requirements
+├── Error response formats
+└── Rate limiting info
+```
+
+## Good Documentation Has
+
+```
+Essentials:
+├── Quick start / Getting started
+├── Authentication guide
+├── Complete API reference
+├── Error handling guide
+├── Code examples (multiple languages)
+└── Changelog
+```