We have all been there. Your software keeps growing and you feel the need to make it customizable. It is too soon for a full-blown UI with all the bells and whistles, so your pragmatic instinct suggests a text-based configuration file. Yes, that’s exactly it!
You rejoice knowing the software’s configuration will be trivial to version control. Your pragmatic instinct is satisfied as well; the door remains open to creating a proper UI later, since it would be merely a graphical view of your configuration’s structured data.