grammatical error on read me.

README.md

@@ -3,6 +3,6 @@ Simba
 
 [![Build Status](https://travis-ci.org/MerlijnWajer/Simba.svg?branch=master)](https://travis-ci.org/MerlijnWajer/Simba)
 
-Simba is a program used to repeat certain (complicated) tasks. Typically these tasks involve using the mouse and keyboard. Simba is programmable, which means you can design your own logic and steps that Simba will follow, based upon certain input such a colours on the screen
+Simba is a program used to repeat certain (complicated) tasks. Typically these tasks involve using the mouse and keyboard. Simba is programmable, which means you can design your own logic and steps that Simba will follow, based upon certain input such as colours on the screen
 
 This file is a stub. For more information, see http://wizzup.org/simba/