create a .gitignore when creating templates

[ninjamuffin99]

i get trolled when I have to create a gitignore each time!

my suggestions for what to put into it

# we usually never want to commit contents from export/ folder
export/ 

# .haxelib/ is for use with local haxelib installs
# https://lib.haxe.org/documentation/using-haxelib/#newrepo
# common use case, the hmm tool uses it for library management
.haxelib/

# self explanatory... 
.DS_STORE