Revert "Revert ":circus_tent: Added .gitattributes""

This reverts commit e959065be97324689505eae95c5b693047ef0f98.
Revert "Revert "Apprentissage HTML5 et CSS3 Karine""

This reverts commit a56f3549b824b8c1bc6a7a492e4dd7bb70ba8c51.