added 'singleTap' event to README

README.md

@@ -215,7 +215,7 @@ Single Tap:
 
 Only use this instead of "tap" if you're using the "doubleTap" event. It it will give you a 250
 ms buffer to be able to differentiate between a single tap and a double tap. Don't use it if you're not
-using "doubleTap" since it will cause a 250ms delay, which could lead to a bad user experience.
+using "doubleTap" since it will cause a 250 ms delay, which could lead to a bad user experience.
 
 ``` js
 $('some selector').singleTap(function(){ ... });