PreviewCard does not use a fallback thumbnail icon

[rahultiru]

According to the documentation of PreviewCard, the imageUrl prop "Will display on the left of the PreviewCard. If not provided the image will be replaced by an icon depending on the file type."

That doesn't seem to be the case.

With imageUrl:

Without imageUrl:

[swese44]

ah, this was the intended implementation but this component was built before the Illustration components were built into YamUI. we should remove that description