add uswds assets; update home layout; reorganize file structure

Closes #2 and #3

Moved CSS and JS into their own folders
Downloaded the US Web Design Standards assets
Restructured Home to coincide with the new assets

More still needs to be done, but I wanted you to have a chance to see (and merge) the big changes. I will continue to update the other pages, which I will submit issues that I'll assign to myself.

QA:

[ ] Visit home page to be sure it appears
[ ] Verify AJAX functionality still pulls in results

ddcornwall / nara-alaskana

add uswds assets; update home layout; reorganize file structure #4