Make index.php files and header management easier

[Quetzacoalt91]

We request all PrestaShop modules provide a index.php files in each folder. This tool (https://github.com/jmcollin/autoindex) can do it automatically, but we should provide it via packagist to make its installation & use automatic.

Also, we should have a tool (which currently does not exist) which could maintain the headers of a whole project easily.