Provide a Stack Component

[tay1orjones]

Since components should no longer have any outside/external "[harmful margin](harmful margin)", there is an even greater need than before for a helper of some type to provide consistent vertical spacing between elements.

The most common solution for this is a Stack component, as popularized by Braid Design System and others.

In essence, this component accepts children and a spacing prop (mapping to our spacing tokens). When rendered, this component will place the spacing amount provided by spacing between the children.

For example:

<Stack spacing="spacing-04">
  <Button>One</Button>
  <Button>Two</Button>
  <Button>Three</Button>
</Stack>

This would render three buttons, each with appropriate margin or padding spacing these equally apart vertically. The first would not have unnecessary top spacing applied, the last would not have unnecessary bottom spacing applied.

We should also update the style guidelines to include a blurb about not using outside margin when styling components.

[joshblack]

@tay1orjones I have some code for this that I can push up in a draft PR real quick 👀

[joshblack]

Link: #9876

[joshblack]

Closed by #9876