Update README to state this element is no longer maintained
Update README to state this element is no longer maintained

I had a great pleasure writing and maintaining `iron-lazy-pages`, but the custom elements landscape has improved so much that `iron-lazy-pages` serves little purpose. Thank you for using my element and feel free to fork if you want to keep on maintaining it.
TimvdLippe/iron-lazy-pages,TimvdLippe/iron-lazy-pages