refactor(config): decouple logging config and update readme

Refactors internal/config to use logging.Config directly, removing duplication. Updates README.md to reference configuration documentation.

cmd/app/main.go

@@ -28,9 +28,7 @@ func main() {
 	}
 
 	// Setup Logger
-	logging.Configure(logging.Config{
-		Level: cfg.Logging.Level,
-	})
+	logging.Configure(cfg.Logging)
 
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()