Draft switch design pattern

[ZoeBijl]

Add guidance on how to code a switch (as opposed to a checkbox). Articles on this:

When to Use a Switch or Checkbox

Preview of branch with work in progress

Switch pattern in switch branch

[mcking65]

Yes, this should have been in the plan for the CR release so adding it to that milestone.

[mcking65]

Thanks to @jongund, we now have a
Switch pattern in the switch branch.

This is ready for task force review.

[annabbott]

No issues noted.