Add i18n

[finkiki]

Could be nice to have i18n and choose the language interface I want in the settings.
I can't help with the code, but I can help translate into french and a little bit with Italian

[ferg1e]

Thank you for volunteering to do some of the French translating.

I had been thinking about adding other languages besides English for the interface. But it seems hard. We can start small.

What do most people use to translate content? Can that same tool be used to translate interface?