Added Additional Reading to vestibular disorders page.

Created by: ivagold

This article gives clear examples and helpful tips on how to use animation in ways that are less likely to make people sick. It's essentially an in-depth version of this page's "What should you consider?" blurb. I think it's worth linking to!

_posts/2013-05-15-understanding-vestibular-disorders.md

@@ -27,3 +27,6 @@ The cause may be from illness, injury, or from a genetic anomoly but anyone can
 ##What should you consider?##
 
 Don't make animations, sliders, rapid movement start automatically. Give an indicator of what movement will happen on the site when a user takes action. Allow the user the option to turn off any animation and movement.
+
+##Additional Reading##
+- [Designing Safer Web Animation For Motion Sensitivity](http://alistapart.com/article/designing-safer-web-animation-for-motion-sensitivity)