The purpose of this repository is to create template files. One suggested method for using it is to add as a submodule of the repo that you are currently working on.
cd ${REPO_ROOT}
git submodule add git@github.com:CathalHarte/c_cpp_cmake_templates.git
Generally speaking the python3 files contained within can be called from anywhere, and they generate a template file in the current directory. The -h option works for these python files, so use that for more detailed instructions.