typo in README.md

Author: mauriciopoppe

README.md

@@ -19,7 +19,7 @@
 ---
 
 Function Plot is a powerful library built on top of <a href="http://d3js.org/">D3.js</a> whose purpose
-is to render functions with little configuration (think of it as a little clone of Google's plotting
+is to render functions with little configuration, think of it as a little clone of Google's plotting
 utility: [y = x * x](https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&es_th=1&ie=UTF-8#q=y+%3D+x+%5E+2)
 
 The library currently supports interactive line charts and scatterplots, whenever the graph scale is modified the function