📝 docs: add GITMOJI_CHEATSHEET.md and reference in README

- Created comprehensive Gitmoji cheatsheet in documentation/
- Added quick reference to README for common Gitmoji
- Links to full cheatsheet for all Gitmoji options
- Helps team use consistent commit message format

This provides:
- Quick visual reference for common Gitmoji
- Examples of good/bad commit messages
- Best practices for commit formatting
- Easy access to full reference when needed

No more guessing which Gitmoji to use!

Refs: #documentation, #gitmoji, #conventions

documentation/GITMOJI_CHEATSHEET.md

@@ -0,0 +1,136 @@
+# Gitmoji Cheatsheet
+
+## 🎯 Purpose
+
+Quick reference for using Gitmoji in commit messages. Follows the [Common Gitmoji Reference](https://gitmoji.dev/) standard as documented in [AGENTS.md](../AGENTS.md).
+
+## 📋 When to Use Gitmoji
+
+**Always use Gitmoji** for:
+- Feature commits (`✨ feat:`)
+- Bug fixes (`🐛 fix:`)
+- Documentation (`📝 docs:`)
+- Refactoring (`♻️ refactor:`)
+- Build/config changes (`🔧 chore:`)
+
+**Format:** `📝 docs: brief description of changes`
+
+## 🔑 Common Gitmoji
+
+### Feature & Bug Changes
+```
+✨ `:sparkles:` - New feature
+🐛 `:bug:` - Bug fix
+♻️ `:recycle:` - Code refactoring
+🔥 `:fire:` - Remove code/files
+🚀 `:rocket:` - Performance improvements
+🔒 `:lock:` - Security fixes
+```
+
+### Documentation & Style
+```
+📝 `:memo:` - Documentation changes
+🎨 `:art:` - Code formatting/style
+📦 `:package:` - Dependency changes
+```
+
+### Testing & CI/CD
+```
+🧪 `:test_tube:` - Tests
+🤖 `:robot:` - CI/CD changes
+```
+
+### Platform-Specific
+```
+🐧 `:penguin:` - Linux changes
+🍎 `:apple:` - macOS changes
+🪟 `:window:` - Windows changes
+```
+
+### Other Common
+```
+📈 `:chart_with_upwards_trend:` - Analytics/SEO
+🌐 `:globe_with_meridians:` - Internationalization
+⚡ `:zap:` - Performance improvements
+🔌 `:electric_plug:` - Add/remove dependencies
+🏗️ `:building_construction:` - Architecture changes
+```
+
+## 📖 Examples
+
+### Good Commit Messages
+```
+✅ 📝 docs: add AGENT_USAGE_GUIDE.md with launch commands
+✅ ✨ feat: implement OAuth authentication with JWT
+✅ 🐛 fix: resolve CI workflow validation error
+✅ ♻️ refactor: extract payment service from monolith
+✅ 🧪 test: add BDD scenarios for authentication
+✅ 🔧 chore: update go.mod dependencies
+```
+
+### Bad Commit Messages
+```
+❌ No gitmoji: "add documentation"
+❌ Wrong gitmoji: "📖 docs: add guide" (should be 📝)
+❌ Too vague: "📝 docs: update"
+❌ Too long: "📝 docs: add comprehensive guide with examples and references and usage patterns"
+```
+
+## 🎯 Best Practices
+
+### 1. **Be Specific**
+```
+❌ "📝 docs: update README"
+✅ "📝 docs: add agent launch commands to README"
+```
+
+### 2. **Use Imperative Mood**
+```
+❌ "📝 docs: added guide"
+✅ "📝 docs: add guide"
+```
+
+### 3. **Keep It Short**
+```
+❌ "📝 docs: add comprehensive documentation guide with examples and references"
+✅ "📝 docs: add AGENT_USAGE_GUIDE.md"
+```
+
+### 4. **Link to References**
+```
+✅ "✨ feat: implement payment system (#42)"
+✅ "🐛 fix: CI workflow error (see #45)"
+✅ "📝 docs: update README (ref adr/0008)"
+```
+
+## 🔍 How to Check Gitmoji
+
+### Using the commit-message skill
+```bash
+# Validate a commit message
+skill commit-message validate \
+  --message "📝 docs: update changelog guide" \
+  --file .git/COMMIT_EDITMSG
+
+# Get suggestions
+skill commit-message suggest \
+  --type "documentation" \
+  --description "update changelog guide"
+```
+
+### Quick Reference
+```bash
+# List all gitmoji
+skill commit-message list-gitmoji
+
+# Check specific type
+skill commit-message suggest --type "docs"
+```
+
+## 📚 Reference
+
+- [Common Gitmoji Reference](https://gitmoji.dev/)
+- [AGENTS.md](../AGENTS.md) - Project-specific conventions
+- [Conventional Commits](https://www.conventionalcommits.org/)
+
+**Tip:** Bookmark this cheatsheet or use `skill commit-message list-gitmoji` for quick reference!