Tabbing Accessibility

[ryansoeder]

Love this project! Easy to install and get running out of the box. Great functionality and features, especially as a fancybox user.

The only thing that keeps me from using it professionally is the lack of tabbing access for users who don't use a mouse. I have a solution that I think answers the basic need and will make a pull request. Of course, there's always more work to be done to make beautiful components like this accessible but let's get the ball rolling!