zsh: switch to yadm for dotfile management

.zsh/config.zsh

@@ -3,7 +3,11 @@ if [ -f ~/.dircolors ]; then
 fi
 alias ls="ls --color=auto --group-directories-first -F --quoting-style literal"
 
-alias config='git --git-dir=$HOME/.dotfiles/ --work-tree=$HOME'
+if whence -p yadm > /dev/null; then
+  export YADM_OVERRIDE_REPO="$HOME/.dotfiles"
+else
+  alias yadm='git --git-dir=$HOME/.dotfiles/ --work-tree=$HOME'
+fi
 
 autoload -U compinit && compinit