Shamelessly stolen from emilyst/home. See their README.md for the decisions behind this approach to managing the home directory.
Set the inital alias.
alias home="git --work-tree=$HOME --git-dir=$HOME/.home.git"
Bootstrap the repo.
home init
home remote add origin git@github.com:kirisu/home.git
home fetch --all
home reset --hard origin/master
home submodule update --init --rebase