Squashed 'zsh/antigen/' content from commit 95a3165

git-subtree-dir: zsh/antigen
git-subtree-split: 95a3165d82b7eee1b6dc7b68766beb9f5db63d7c
Merge commit '24602f0678eb4df617fdedfa974c9477d284f5d4' as 'zsh/antigen'
initial