patch 9.1.1494: runtime(tutor): no French translation for Chapter 2

patch 9.1.1494: runtime(tutor): no French translation for Chapter 2

Problem:  runtime(tutor): no French translation for Chapter 2
Solution: add and refine French translation of tutor2, update French
          vimtutor manpage (Damien Lejay)

- Add runtime/tutor/tutor2.fr.utf-8
- Improve translation based on review
- Update references in tutor1.fr and vimtutor-fr.1
- Adjust MAINTAINERS accordingly

closes: #17546

Co-authored-by: Gabriel Dupras <57042631+gdupras@users.noreply.github.com>
Signed-off-by: Damien Lejay <damien@lejay.be>
Signed-off-by: Christian Brabandt <cb@256bit.org>