How to translate my theme?
1. POEdit is a free software for translating WordPress theme easily. You can download it here.
2. Open POEdit and File > New From POT/PO File...
3. Choose en_US.po file from jay/languages folder in your theme.
4. Choose the language you're translating to from the list and click OK. For example, if you're translating your theme to German, choose German (Germany).
5. Now begin translating strings. You don't have to translate every string in the list. Just search for the string you need and translate them.
6. After translating all strings you need, save this file in jay/languages folder. File name format must be in a following format.
[language code]_[COUNTRY CODE]
For example, if you're translating your theme to German (Germany), file name is de_DE. Please see language codes from here and country codes from here. If you did it right, there should be 3 files in jay/languages folder which are en_US.po, de_DE.po, de_DE.mo. Please note that if you translated your theme to a different language than German, de_DE.po and de_DE.mo file names will be different.
7. Choose your site language from Settings > General > Site Language.