设置静态文件路径
访问静态文件需要先设置路径
func main() {
    router := gin.Default()
    router.Static("/assets", "./assets")
    router.StaticFS("/more_static", http.Dir("my_file_system"))
    router.StaticFile("/favicon.ico", "./resources/favicon.ico")
    // Listen and serve on 0.0.0.0:8080
    router.Run(":8080")
}