Add JS list-cycle assignment.

Add:
	index.html
		-simple page with a short ul of numbers, and a button that, when
		pressed, will cycle a color through the list items.

	dynamic.js
		-assigns cycle function to event of button click. cycle() cycles once
		through the ul's list items, toggling their .colored class.

	style.css
		-add .colored, which is added to the cycle's current list item.