Breadcrumb items as buttons documentation

[whatnextjamie]

Description

Add example documentation for USDA-FSA/fsa-style#566

Completed and waiting in: https://github.com/USDA-FSA/fsa-design-system/tree/release/1.20.2

Just need to verify everything looks correct once fsa-style can be updated to 2.7.5 or greater in fsa-design-system