References: Add downloadable references to Top Nav Bar

[chad-cognition]

• DECISION: Icon in top nav bar to pull/show references for whatever appears on the page catalogued in a way that mirrors what's on the page.
• Export as CSV so they can filter on their own
• ACTION: Chad to mock this up and share with Ryan (reference original wireframe for new design https://projects.invisionapp.com/d/main#/console/10954039/237561934/preview)