docs: update readme according to how latest code behaves

Author: Vinit Kumar

README.rst

@@ -75,7 +75,7 @@ Outputs this:
 
 .. code-block:: xml
 
-    <?xml version="1.0" ?>
+    <?xml version="1.0" encoding="UTF-8"?>
     <all>
       <login type="str">mojombo</login>
       <id type="int">1</id>