- typo fix in readme

Author: ecarriou

README.md

@@ -10,7 +10,7 @@
 
 #### a System Runtime Environment
 
-[JSON](http://json.org) is traditionnaly used to represent data. We use this format to store the model, components and methods of your application. Runtime can run JSON that contains your application as a SRE (Sytem Runtime Environment).
+[JSON](http://json.org) is traditionnaly used to represent data. We use this format to store the model, components and methods of your application. Runtime can run JSON that contains your application as a SRE (System Runtime Environment).
 
 Runtime has APIs to serialize your JavaScript code into JSON. This JSON can be then imported and executed in a client or server application.