Fix for first animation frame always showing the first sprite sheet texture region rather than the first animation's texture region. (#972)

Co-authored-by: Christopher Whitley <103014489+AristurtleDev@users.noreply.github.com>

source/MonoGame.Extended/Graphics/AnimatedSprite.cs

@@ -51,6 +51,7 @@ public class AnimatedSprite : Sprite
     {
         _animation = spriteSheet.GetAnimation(initialAnimation);
         Controller = new AnimationController(_animation);
+        TextureRegion = _spriteSheet.TextureAtlas[Controller.CurrentFrame];
     }
 
     /// <summary>