I had not seen this yet, and it is not on the main rules page for the Age of Sigmar. This was sent in by a reader, and its the Island of Blood for the Age of Sigmar, and contains Warscrolls for the High Elves and Skaven.
Island of Blood
http://trade.games-workshop.com/wp-content/uploads/2015/07/Island-of-Blood-AoS-Warscrolls-Compendium.pdf