feat: add git cheatsheet

README.md

@@ -36,6 +36,8 @@ Each module is a self-contained challenge that teaches specific git concepts:
 5. Run `./verify.ps1` to check if you've solved it correctly
 6. Move to the next module
 
+**Quick Reference**: See [GIT-CHEATSHEET.md](GIT-CHEATSHEET.md) for a comprehensive list of all Git commands covered in this workshop.
+
 ## Requirements
 
 - Git installed and configured
@@ -98,6 +100,7 @@ The modules are designed to build on each other:
 
 - Don't skip modules - each builds on previous concepts
 - Read the README.md thoroughly before starting each challenge
+- Keep [GIT-CHEATSHEET.md](GIT-CHEATSHEET.md) open as a quick reference
 - Experiment freely - you can always run `./reset.ps1` to start over
 - Use `git log --oneline --graph --all` frequently to visualize repository state
 - If stuck, check the Key Concepts section in the module's README