Add styling for code highlighted code blocks

[dannyBies]

Currently, highlighted code blocks do not have the same styling as normal code blocks.

``` public class AVeryLongClassNameWillOveflowTextWithoutShowingAScrollBar : BugInStyleSheet {

} ```

```C# public class AVeryLongClassNameWillOveflowTextWithoutShowingAScrollBar : BugInStyleSheet {

} ```

If you use the above markdown you get the following output: Note the missing scrollbar. When you add a highlighted code block the \

 gets wrapped in a div which causes the styling to not apply because it only looks for direct descendants of \
 (#container main article > pre )

This fix applies the relevant styling to a highlighted code block.
            

[funkydan2]

Thanks!