These are a wonderful way to keep track of the plethora of configuration files that you'll undoubtedly set up while working as a developer, and quickly install them on another machine. Nothing like having your environments on your home and work boxes be the same!
If you want a nice baseline of configuration for your .zshrc, .vimrc, .gitconfig, .aliasrc, .tmux.conf, and many others, my dotfiles repo is a very quick setup that allows you to granularly pick exactly the files you want.
I recommend forking my repo to your Github account, cloning to your home directory, and then running the install script.
git clone email@example.com:Lordnibbler/dotfiles.git ~/.dotfiles # follow the prompts ~/.install.sh
From here, you can adjust the dotfiles to your liking, keep them up to date, and safely backed up on Github!