Add automatically the corresponding ISO 639 Language Code to generated srt files. The ISO 639 Language Code is used by media players (e.g. VLC) and media servers (e.g. Plex) to figure out which language the subtitle is.
Example:
The movie file 'The King 2 Hearts (2012) {tmdb-46528} - s01e04.mp4' generates 'The King 2 Hearts (2012) {tmdb-46528} - s01e04.en.rst'