Mengelompokkan route
func main() {  router := gin.Default()
  // Grup sederhana: v1  {    v1 := router.Group("/v1")    v1.POST("/login", loginEndpoint)    v1.POST("/submit", submitEndpoint)    v1.POST("/read", readEndpoint)  }
  // Grup sederhana: v2  {    v2 := router.Group("/v2")    v2.POST("/login", loginEndpoint)    v2.POST("/submit", submitEndpoint)    v2.POST("/read", readEndpoint)  }
  router.Run(":8080")}