Simplify zsh completion

Completion file shouldn't be sourced. It should provide only completion
code (source of _command) for command. It's task for package manager or
user to put under $fpath.

autocomplete/zsh_autocomplete

@@ -1,7 +1,5 @@
 #compdef $PROG
 
-_cli_zsh_autocomplete() {
-
 local -a opts
 local cur
 cur=${words[-1]}
@@ -16,8 +14,3 @@ _cli_zsh_autocomplete() {
 else
   _files
 fi
-
-  return
-}
-
-compdef _cli_zsh_autocomplete $PROG