Documentation (and examples) for: to, do, back

[SquirrelModeller]

Description
The documentation, to my knowledge, lacks information on the property: do

One scenario where this documentation would be useful would be for showing how to execute code after an action is performed.

An example would be removing an element after an action is performed:
yield node.opacity(0, 1).do(() => node.remove())

I suggest adding examples of how these properties are used in the "docs" section. The property back is already demonstrated in the section "Scene hierarchy". Likewise to is demonstrated in "Animation flow". It seems inconsistent to omit do. I also suggest pooling the properties together and explaining them all.