KordEx makes all the strings returned via the bot translatable by default. In practice, this means that all the string are defined in resources/translations/botfest/strings.properties and accessed using, for example, Translations.Commands.Group.Admin.description. How this works is that KordEx will generate code matching the translation strings. Note that your IDE might get confused until you build the project. Afterwards the translations should show up just fine.

For more information on translations, formatting, etc, please refer to the KordEx documentation on the topic