add a new problem to be solved with multiple images
solved first problem with background-position property
fixing the bg-position to use the correct image
add another problem to be solved with sprites and hover
solved problem changing bg-position at :hover or :focus
Merge branch 'master' into sprightly-slaloms

Conflicts:
	README.md
Merge pull request #13 from helmedeiros/sprightly-slaloms

Learned about background-position and sprites