Float Week #2

This variation of today's cartoon adds more to the "Float Week" content (today's and the one coming up on Thursday).

The `clear` property defines how an element will be positioned (and if it needs to be moved below or cleared) depending on the floating elements that precede it. In the case of the cartoon, both fish have `float`, so by applying `clear: both` to the second fish, it will move below the other one... clearing the way and giving more swimming space for both fish.

Initially, I was thinking about doing a "rougher version" in which a fish tells the other to "clear off", but the float reference could not be as clear, and it sounded rude. And these fish are cute and friendly to each other :P

I hope you like it.