add example animation to README

Author: CGJennings

README.md

@@ -1,8 +1,10 @@
 # FJS string searching algorithm sample code
 
+![animation of the algorithm finding pattern "aabaa" in text "aabaabaaba bab aaabaa"](readme/images/fjs-animation.gif)
+
 String search algorithms find occurrences of a pattern string in a text, like the search feature of a text editor. The FJS (Franek-Jennings-Smyth) algorithm is the fastest known string search algorithm under a wide variety of conditions. It combines the linear-time worst case guarantee of the well-known KMP (Knuth-Morris-Pratt) algorithm with the fast average-case performance of the BMS (Boyer-Moore-Sunday) algorithm.
 
-[More information, including an interactive demo of the algorithm in action.](https://cgjennings.ca/articles/fjs.html)
+[More information, including an interactive visualization.](https://cgjennings.ca/articles/fjs.html)
 
 ## The sample code