Fix module title's font size

[dcwhite]

As a section title, it should be bigger. It's smaller than some of the sub-section titles, and the same size as the normal text below it:

[dcwhite]

Alternatively, we can totally rewrite the module doc's page structure to be more like a tree menu on the left, just like SCIRun's module selector. Thoughts? @jessdtate

[dcwhite]

That would move the module title to a different list, and then this issue would be moot.