Changing how footsteps are added/animated

Removed manually adding the footsteps to make the HTML much less
cluttered; added them with a for loop through jquery. Same thing with
the animation.

This is only for the left side footsteps for now, but I’m doing it for
the other two sections (middle and right) too.
Merge branch 'master' of https://github.com/yeamal/UnclassProject

Conflicts:
	script.js