Inconsistencies between motivations types (list, string) in Content State API

[giacomomarchioro]

Hi all, Although in https://www.w3.org/TR/annotation-model/ motivation is always followed by a string in Content State API it is always a list, except for the Multiple targets section where motivation value is a string e.g.:

"motivation": "contentState", instead of "motivation": ["contentState"],

Should they be uniformed?