[W3C] Summary issue

[alexisben]

Vérifier ces nouvelles erreurs du W3C markup validator.

Element “summary” is missing one or more of the following attributes: “aria-checked”, “aria-level”, “role”.

The “aria-expanded” attribute must not be used on any “summary” element that is a summary for its parent “details” element.

[alexisben]

https://github.com/validator/validator/issues?q=label:aria-conformance

validator/validator#1930