Attempted to implement Andrea's main.css:
colours, fonts, etc. Not fully working yet.

	modified:   _layouts/jumbotron-narrow/index.html
	modified:   _layouts/jumbotron-narrow/jumbotron-narrow.css
	modified:   _layouts/jumbotron-narrow/main.css
	modified:   _layouts/jumbotron-narrow/main.less