Fixed compdef alias to use 'gd' as shortcut.

plugins/git/git.plugin.zsh

@@ -4,7 +4,7 @@ compdef g=git
 alias gst='git status'
 compdef _git gst=git-status
 alias gd='git diff'
-compdef _git diff=git-diff
+compdef _git gd=git-diff
 alias gl='git pull'
 compdef _git gl=git-pull
 alias gup='git fetch && git rebase'