Squashed 'files/.zsh/vendor/rupa-z/' content from commit 8053ded

git-subtree-dir: files/.zsh/vendor/rupa-z
git-subtree-split: 8053deda7508b36443f1b57dad1f295dfa60959f
Merge commit '1c73d2c6b6423a1a66580cc0489c633c65a8c618' as 'files/.zsh/vendor/rupa-z'
subtree setup for z script
Adding the z.sh setup
Adding reference to git subtree blog post