Juanpe/SkeletonView ? reverse-engineered prompt

Build me a Swift library for iOS that shows skeleton loading placeholders while real content is still being fetched. I want it to work on normal views, view controllers, table views, and collection views, so I can turn it on for a whole screen and have the skeleton appear recursively on the child views too.

It should be easy to use with just a few calls, support solid and gradient placeholders, and include animated versions of both. Make it customizable enough to change the appearance and colors, and friendly for Storyboards or Interface Builder too. The table view and collection view support should feel natural, so I can swap in the skeleton data source behavior when loading and then return to the real content afterward.

Please make it clean, lightweight, and well documented, and include a simple example app or demo screen that shows how to use it. If you need current docs or platform details, look them up online first.