This is a collection of file templates for Xcode.
Clone this repository somewhere on your filesystem, and then execute the following command from the newly-cloned repository directory:
ln -s "$PWD"/File\ Templates ~/Library/Application\ Support/Developer/Shared/Xcode
If you already have a File Templates directory in that location, you may instead choose to symlink each individual subfolder in to the existing directory:
for f in "$PWD"/File\ Templates/*; do
ln -s "$f" ~/Library/Application\ Support/Developer/Shared/Xcode/File\ Templates/
done
In Xcode select the File->New File… menu item. There should be a section called "User Templates" which contains all of the file templates.