Updated search page

[edsu]

I wonder if we should reconsider using the default search page, with our added featured collections, since pywb 2.7 now has help text and the usability is improved? I think this may help us as we move forward with upgrades as well?

See: webrecorder/pywb#794

@peterchanws would it be helpful to see what it would look like in Stage or QA?