PermissionRequiredMixin docs are inconsistent with upstream behaviour

[LegoStormtroopr]

From this: https://django-braces.readthedocs.io/en/latest/access.html#permissionrequiredmixin

This mixin was originally written by Daniel Sokolowski (code here), but this version eliminates an unneeded render if the permissions check fails.

Reviewing the linked code the PermissionRequiredMixin does not do object permissions, while the djang-guardian version does.

This means that PermissionRequired with an UpdateView may incorrectly allow a user through.

Either the documentation should be updated, or the code should. Happy to do a PR.