Remove old oh-my-zsh install
Squashed 'oh-my-zsh/' content from commit 3913106

git-subtree-dir: oh-my-zsh
git-subtree-split: 3913106b2e7127d396f27b652df812340ec0c871
Merge commit '81017bd1ff1edddb12c9dca20a7b9f3dac24df69' as 'oh-my-zsh'
Re-add zsh theme
Update README for new oh-my-zsh subtree setup