Article Audit: ARIA States & Properties articles

Created by: scottaohara

While reviewing the ARIA States and Properties articles, I noticed that the linked resource of the different attributes doesn't match the ARIA 1.1 specification, which lists more attributes. For instance, aria-modal and aria-details are missing from the linked resource (and the properties article), but are present in the published ARIA 1.1 spec.

These articles should be reviewed to make sure there aren't any other attributes that are missing.