The Localizer stores the translation files in the TRANSLATION_DIR (specified
in the config file).  The TRANSLATION_DIR has a subdirectory for each language:
  /en
  /de
  /fr
  ...etc...

Within each directory is a set of files, the format of these files may be
different depending on which file format you are using.  You can load a
file by specifying the file's prefix like so:

Localizer::LoadLanguageFiles('articles', 'en');

