i18n support

[IAmJSD]

This is one for the "future ideas bucket list" and there's a lot more before it, but it has been on my mind so posting it here. It'd be really cool to get multi language support for this so that it is accessible to non-English speakers. Codebase wise, this isn't incredibly complex (apart from Arabic due to RTL text). The complexity is that some languages may need to be async added and we'd also need people to contribute strings for various languages (I can only maintain English and Swedish).

[IAmJSD]

One mild form of this we might have to worry about if we do dates (say for history) in the future is we should probably support UK and US date formats. It is extremely confusing for someone who is used to en-GB to look at a en-US date.