Explained outputFormat options in readme.

README.md

@@ -27,8 +27,13 @@ as the second argument when constructing. For example:
 
     var calais = new Calais('<YOUR API KEY>', {'cleanResult': false})
 
-Any Calais input parameter can be passed, as well as the 'cleanResult' parameter
-(which can be set to false to show the raw Calais result).
+By default, node-calais will return fetched results as a Javascript object.
+Alternatively, the Calais standard "outputFormat" input parameter can be set to
+standard output formats (see Calais documentation).
+
+Any standard Calais input parameter can be passed as an option, as well as the
+'cleanResult' parameter which will return a simplified Javascript object if
+"outputFormat" hasn't been set to something other than the default ('object').
 
 ## Test ##