Update Contributing Guide

Contributing-Guide.md

@@ -1444,7 +1444,7 @@ make update               # Update all dependencies
 make freeze               # Generate requirements-frozen.txt
 ```
 
-## Git Workflow
+### Git Workflow
 
 ```bash
 # Start new feature
@@ -1467,7 +1467,7 @@ git pull origin main
 git branch -d feature/feature-name
 ```
 
-## Common Tasks
+### Common Tasks
 
 **Add new slash command:**
 1. Add command in `pterodisbot.py` with `@bot.tree.command()`