Content translation to fr (activities)

This is a Work In Progress :

- [x] Activities 1-5 (@real34)
- [ ] Activities 6-10 (@real34)
- [ ] Activities 11-15
- [ ] Activities 16-20
- [ ] Activities 21-25
- [ ] Activities 26-30
- [ ] Activities 31-35
- [ ] Activities 36-40
- [ ] Activities 41-45
- [ ] Activities 46-50
- [ ] Activities 51-55
- [ ] Activities 56-60
- [ ] Activities 61-65
- [ ] Activities 66-70
- [ ] Activities 71-78