Markup and style fix

[tallys]

"First Pull Request" issue -

On http://tallys.github.io/color-theory/ on the final example, there was some erroneous padding around the header added in a hurry, but it doesn't look the same as the rest of the sections. Remove the final-example class from both the markup and the styles.

Currently it looks like:

It should look like this:

Ping me if you need a hint!