Add initial project structure with database connection and routing setup

- Create .env.example and .gitignore to manage environment variables
- Implement database connection logic in bd.go
- Define project model and data retrieval functions in projet.go
- Set up HTTP routes for project management in routes/projet.go
- Add main entry point in main.go to start the server

go.mod

@@ -0,0 +1,10 @@
+module api_serveurless_go
+
+go 1.25.1
+
+require (
+	github.com/go-sql-driver/mysql v1.9.3
+	github.com/joho/godotenv v1.5.1
+)
+
+require filippo.io/edwards25519 v1.1.0 // indirect