Add internationalization (i18n) support for multilingual UI (especially Chinese)

[tachikoyu]

HI, I'm from China and been playing with it, but everything's in English with those hardcoded strings. A bunch of us Chinese photographers would go nuts for a Chinese version (and probably other languages too).

Any chance we could toss in some i18n support? Like react-i18next or whatever's easy – just so we can slap translations in JSON files instead of hacking the code every time.

[Kondorfire]

It's an excellent idea, since many of us could help with the translations, making it easier to internationalize the program and reach more people.

[YannBirba]

Yeah I'm ready to be involved in this also