NodeList

I tried using this for a unit-test, and ran into some issues with e.g. `childNodes`, which in regular DOM is a [NodeList](https://developer.mozilla.org/en-US/docs/Web/API/NodeList) and not just an `Array`, which is missing, for example, the `keys()`, `values()` and `entries()` iterator methods.

I can foresee issues as well with e.g. `children` being a plain `Array` created by filtering `childNodes` - whereas, in regular DOM, mutating the `childNodes` of the parent that generated the `children` collection, would cause the iterator to reflect those changes.

Maybe this is "by design", favoring simplicity over correctness?

If so, that isn't clear from the "Project Goals" stated in the README right now - it doesn't seem to imply that this deviates from DOM in terms of more than features.

Lacking features is a matter of scope - but incompatibilities probably ought to be designated in the documentation?

Commencez par les Project Goals du README et examinez comment childNodes et children sont actuellement produits. Comparez le comportement avec les méthodes keys(), values() et entries() de NodeList ainsi qu’avec les attentes signalées en matière de mutation/liveness. La tâche est terminée lorsqu’une décision claire est prise concernant le périmètre de compatibilité, avec soit des divergences documentées, soit une modification d’implémentation ciblée et des tests.

Rédigé par le modèle d'indexation à partir du texte de l'issue.