Note: Please if you already knew the translation files go here to translate the theme and plugin.
The theme and nd-shortcodes plugins are “localization-ready”, this it means that you can translate them in your language easily.
For the translation the “Text Domain” it is really important since you use it for denote all text belonging to that theme and it have to match the “slug” of the theme. The text domain name must use dashes and not underscores and be lowercase.
For properly translate the theme you need to know your “language code” and/or country code that you have set as default language in: Dashboard > General > Site Language.
Language code list here.
File types of the translation