Finish draft of lessons related to Collaboration Campfires

[hturner]

We created drafts of lesson material based on the Collaboration Campfires:

https://github.com/r-devel/r-bug-tracking-lesson
https://github.com/r-devel/r-translations-lesson

Would be nice to complete these if possible, with priority given to the bug tracking lesson (translation one may be less relevant now Weblate is recommended to new contributors).