Define focus state for expandables

[nataliafitzgerald]

In referencing the Expandables page on the CFPB Design Manual we do not appear to have defined standards that indicate how the focus state should be visualized. And, in viewing our expandables, there is inconsistency between how the focus state is rendered on:

• cf.gov pages
  
• CFPB Design Manual
  
• Capital Framework
  

Need: Define the visual design cue for the focus state, add this to the Design Manual, and implement so that there is consistency across cf.gov, Capital Framework, and our Design Manual.