Here's a description of how my dotfiles work.
git clone https://github.com/nlhenry/dotfiles
cd <this-repo>
./install/bootstrap.sh
If there's customization you want ZSH to load on startup that is specific to
this machine (stuff you don't want to commit into the repo), create ~/.env.sh
and put it in there. It will be loaded near the top of .zshrc.