Add option to choose homepage language

[paulfalgout]

https://github.com/marionettejs/backbone.marionette/issues/2654

I agree too.. as a guy who lived for years in Korea but spoke no Korean, this would've been frustrating (assuming there is/was a Korean translation)

[samccone]

sure ok https://github.com/marionettejs/marionettejs.com/pull/400/files

[paulfalgout]

ping @blikblum