Add myctl ZSH alias

Typing `systemctl --user restart emacs' at least once a day and often
also `systemctl --user start mpd' is annoying. `systemctl' is for
system-wide unit files, `myctl' just for my own.

zsh/.zshrc

@@ -31,6 +31,7 @@ alias ls="ls -F --color=always"
 alias mysql="mysql --pager"
 alias sbcl="rlwrap sbcl"
 alias scrot="/usr/bin/scrot -e 'mv \$f ~/pictures/screenshots/'"
+alias myctl="systemctl --user"
 
 # Suffix aliases
 alias -s pdf="zathura"