WIP: Add showcase page with a book partial and add form for creating a new book

@cgruppioni @chukdisc 

Still a WIP, will need a lot more work. Would like to get feedback on the current code.
Be careful using floats when working with neat.  Remember to rescale the size of your window to make sure your app stays responsive at other screen sizes.  Sometimes, add custom ("non neat") positioning can mess things up.  Not always though, so just something to be aware of.