herbivores expansion

This mod adds extinct and contemporary herbivores from North America and Europe. For now, we have the primitive bison and the latiforns. There are also horses such as the Hippidion and the Western horse, the Booterium, an extinct species of musk ox, and Megaloceros giganteus. This mod will mainly add hoofed mammals, so there is little chance of proboscideans and ground sloths.

   added roe deer and musk deer