Add translations

[seanjhardy]

Restructure skills so the "goals" array contains multiple different language options, and let the user specify which options are set. Maybe even highlight skills to show which ones are complete/uncompleted for a given language. This feature must be interoperable with tips too

[seanjhardy]

Also, add a feature to input a trees, and if they match ID and contain a completed language translation, merge it with the existing tree to add translations