French Translation - JavaScript Chapter (#1218)

* French translation - JavaScript Chapter

Makes progress on #539

* Update src/content/fr/2019/javascript.md

Co-authored-by: Barry Pollard <[email protected]>

* Add translation to featured_chapters

* Fix typo numbers

* Fixes from @nico3333fr 's feedback

Co-authored-by: Barry Pollard <[email protected]>

Author: 2 people