Added a perspective around the outdoor map
More details were added to match the plot
Further reduce the difficulty (except Chapter 3)
Script code optimization
Deleted useless files to reduce map size
Map performance optimization
Visibility optimization

在室外地图周围添加了远景
更多的细节被添加，使其符合剧情
难度进一步降低（第三章除外）
脚本代码优化
删除了无用的文件来减小地图大小
地图性能优化
可见性优化