Help discoverability of `theme.compose` usage with prefix

[tomdye]

When theme.compose (@dojo/widgets/middleware/theme NOT in framework) is used to compose themes together with a prefix these classes are not added to the widget classes list in parade.
It would be useful if parade could detail the widgets that can be targeted within a widget via a prefix.
For example, the @dojo/widgets/typeahead uses a menu prefix for the List that it renders but this is not very discoverable unless you look at the code itself.