@schloerke The internationalization is ready.

I've chosen to leave the question() fun untouched, because as I see it, teachers can still write their own text for the buttons.
And if we chose to add an auto translation here, it would override the setting from `question(), which might be weird.

What's your view on this?

I agree. Let's only change text that learnr has control over.

You are correct in that we should wait on the question text once we have full page translations.

Nice :)

Then, as far as I am concerned, this PR is ready.

Let me know if you want me to change anything

Let's get R CMD check to pass, then we can merge.

The change above should fix it. IDK why I can't commit it.

Great, everything seems good then :)

This is really great work and will make learnr tutorials more approachable for tutorial authors in general and in other languages!

I'd like to propose two additions that would make it easier to change the learnr tutorial language without having to update the learnr package directly (although that should still be encouraged for language translations!).

1. language could accept a list in the expected format, falling back to the English defaults. This would make it trivial to adjust wording of various learnr UI elements from the YAML header of the tutorial:

   ---
   title: "Tutorial"
   output: 
     learnr::tutorial:
       progressive: true
       allow_skip: true
       language:
         button:
           runcode: "Run My Code"
           hints: "Hint, please"
           startover: "Reset"
           previoustopic: "Previous Section"
           nexttopic: "Next Section"
         text:
           startover: "Restart Tutorial"
   ---

2. Alternatively, language could accept a path to a JSON file with the language specification in the expected format.

Superseded by #456

Thank you @ColinFay for such a great start to this feature!