Adds the ability to add a Modal config section similar to nested.
I apologize for lack of tests, but there's currently no JS test. Also I am not a master of the ruby one-liners, so I possibly made code uglier.
I'll close out my other PR. I think this may be the rebase you need... but this time I did not do it in its own branch. Sorry.
Allow Modal Config Section
Thanks! Added brief documentation to Wiki in the vein of Nested...