Translation for Persian/Farsi

[mahdin75]

There's no file for the Persian language.
I can add it to the supported languages.
Can I open a pull request on it?

[1ec5]

Yes, a PR would be welcome. Make sure you pull the translations from Transifex rather than translating the file by hand. It should be based on the fa localization, not the fa-IR localization. See also #289.