Challenge: Speed bumps
Add speed bumps that slow the skateboards down.

Add more skateboards!

Hint

boards.push();
boards.push();

This program simulates a skateboard rolling down a road with minimal friction. We're going to extend it to
show many skateboards rolling down, and slowing down due to a speed bump. To start off with, add more
skateboards to the road, at different masses and positions