The General Configuration File is the js/config.js file. It looks like this :

define([], function() {
 
  return {
    templates: {
      // Does Geckos allow the Edition of the template ?
      editionMode: true,
      // Does Geckos display a List of templates to be selected ?
      listMode: true,
      // Mode that Geckos use by default ('list' or 'edition')
      defaultMode: "list"
    }
  }
});

You need to set either editionMode or listMode to true (or both).

If editionMode is set to true, users will be able to create their own templates, to modify existing ones.

If listMode is set to true, the list of installed templates will be loaded and the user will be able to select one of them.

The defaultMode property accepts list or edition as a value. It defines which screen is displayed by default.