How to use copy this mod into the location of where VoxeLibre is here's an exambple once you go into minetest folder then click on games then go into VoxeLibre then click on mods then go into ENVIROMENT then copy this into there and override the existing mcl_weather for sunray shader support you don't need to copy the readme.md into there also make sutre to extract the mcl_weather out of this before you do the copying.