Add a "SwingSet" or "IMGUI demo" style sample (kitchen sink of what is possible)

[truedat101]

The best example is what IMGUI offers as a sample. It is very kitchen sink and offers great explanations in source about how to use the components:

https://raw.githubusercontent.com/wiki/ocornut/imgui/web/v167/v167-misc.png

[truedat101]

This is kind of existing in "Essentials" in the main project, however, for the most part, Essentials is focused on 2d/3d graphics and not UIKit or SIK specifically. A "swingset" type demo is totally ideal.