docs(08): complete repository structure documentation

Phase 8 - Repository Structure:
- README.md: Updated with Lab 05 completion status
- CONTRIBUTING.md: Contributing guidelines and Conventional Commits
- .gitignore: Comprehensive ignore patterns

Repository now has:
✓ Clear structure for students and instructors
✓ Complete README with all 5 labs documented
✓ Contributing guidelines for future improvements
✓ Proper .gitignore for safety

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,75 @@
+# Editor e IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+.DS_Store
+
+# File temporanei
+*.tmp
+*.log
+*.bak
+
+# Docker
+.dockerignore
+
+# Volumi Docker creati (per evitare commit accidentale)
+/volumes/
+/data/
+
+# File di ambiente (possono contenere segreti)
+.env
+.env.local
+.env.*.local
+
+# File generati
+*.pid
+*.seed
+
+# Directory di build
+dist/
+build/
+
+# Dipendenze node (se usate per test)
+node_modules/
+package-lock.json
+
+# File di backup
+*.backup
+*.old
+
+# File di sistema
+Thumbs.db
+Desktop.ini
+
+# Cache
+.cache/
+*.cache
+
+# Log applicazioni
+logs/
+*.log
+
+# File temporanei di test
+/tmp/
+temp/
+
+# Session data
+.session/
+*.session
+
+# File di configurazione locali (sovrascrivono quelli default)
+*.local
+config.local.*
+
+# File di stato temporanei
+*.state
+*.tmp
+
+# History shell
+.history
+
+# Note personali
+NOTE.md
+PERSONAL.md