Put quote marks around 'poltiicalness', add sentence to explain precision and recall table
Renamed static/politwit to static/css for clarity - this directory contains CSS/SASS styling, now including icons.
Update links to stylesheets using static/css relative path. Add chart legend and instructions, using Foundation icons.

Instructions appear in the main panel on success callback.
Legend appears in the #detail div to the right, instead of earlier placeholder text.
Remove 'hidden' class from #instructions div to show instructions on success callback.