Arkane Studios have revealed that the final add-on pack for the critically-acclaimed first-person action game Dishonored, entitled Dishonored: The Brigmore Witches will be available worldwide on August 13, 2013 for Xbox 360, PS3 (PS3 in Europe on August 14) and PC for £7.99 / €9.99 / AU$14.45 or 800 Microsoft Points. In The…