Advertise "tweak" argument

src/cli/printInfo.go

@@ -25,6 +25,7 @@ This program comes with absolutely no warranty; type "mutn version" for details.
  help                    Bring up this menu
  version                 Display version and license information
  init                    Set up MUTN (generates libmutton.ini)
+ tweak                   Make changes to the libmutton configuration
  copy                    Copy details of an entry to your clipboard
  edit                    Edit an existing entry
  gen                     Generate a new password