Added classes for Gazelle

Signed-off-by: Justin Wiblin <Justin_wiblin@hotmail.co.uk>
Added the gazelle spawns just need to make texture and customize the model

Signed-off-by: Justin Wiblin <Justin_wiblin@hotmail.co.uk>
Merge branch 'Gazelle' into Animals

Signed-off-by: Justin Wiblin <Justin_wiblin@hotmail.co.uk>