Update README.md

Author: Damian Rouson

README.md

@@ -1,7 +1,8 @@
 # Coarray ICAR submission to [PAW17]
 
 ## Prerequisites: 
-LaTeX
+1. LaTeX
+2. Optional: Adobe Acrobat Reader or later for the animated version of Figure 1.
 
 ## Build instructions
 
@@ -20,11 +21,14 @@ pdflatex main && bibtex main && makeglossaries main && pdflatex main
 ```
 
 ## Known Issues
-* Apple Preview will not display the animation.
+* Building the paper with the animated version of Figure 1 requires uncommenting the [`animategraphics` command] in body.tex and commenting the corrsponding `includegraphics` command.
 * LaTeX must compile main.tex twice for Acrobat Reader to display the Figure 1 animation.
+* Apple Preview will not display the animation.
+
 
 See [figures/icar/README.md] for more details on the animation.
 
 [figures/icar/README.md]: figures/icar/README.md
 [PAW17]: http://sourceryinstitute.github.io/PAW/
 [TeXShop]: http://pages.uoregon.edu/koch/texshop/
+[`animategraphics` command]: https://github.com/sourceryinstitute/coarray-icar-paw17/blob/master/body.tex#L33