Add delay for compatability with page transition animations

[ryan-teliczan]

• Scrolling delay parameter.

Ideally, the scroller should delay until the page transition animations are finished.
In my case, I am trying to get this plugin to work with page transition fade animations (gatsby-plugin-transition-link). The issue is that I'm seeing is the scroller starts at the same time as the current page begins to fade out.

I was hoping that I could figure this out and then share the solution with you. But, I can't seem to get it!

Thank you for sharing this plugin. I really like it!

[brohlson]

Seems like a viable enhancement and valid use case - I'll add it to the queue! Thanks @rygnar