remove left over markdown

By observing the [deployed version](http://www.html5rocks.com/zh/tutorials/webcomponents/customelements/) I figured out two left over pieces of markdown, which are not properly removed from the file I pushed.

By the way, I'd like to ask how can I translate the atricle title as well? Since I found the PO/MO files were not maintained for a very long time :(
![title](https://f.cloud.github.com/assets/519733/1861636/5394fa32-77c5-11e3-8cc5-fc810cea7ae8.jpg)