Hello Polyglots! How it’s possible…

Hello Polyglots!
How is it possible to add a new language to the list of the localesLocale Locale = language version, often a combination of a language code and a region code, for instance es_MX denotes Spanish as it’s used in Mexico. A list of all locales supported by WordPress in https://make.wordpress.org/polyglots/teams/?
It’s Ossetic Digorian.