Fix example using named parameter in call

Author: douglas-vaz

README.md

@@ -28,10 +28,10 @@ from react import jsx
 # For multiple paths, use the JSXTransformer class.
 transformer = jsx.JSXTransformer()
 for jsx_path, js_path in my_paths:
-    transformer.transform(jsx_path, js_path)
+    transformer.transform(jsx_path, js_path=js_path)
 
 # For a single file, you can use a shortcut method.
-jsx.transform('path/to/input/file.jsx', 'path/to/output/file.js')
+jsx.transform('path/to/input/file.jsx', js_path='path/to/output/file.js')
 ```
 
 You can also use ``transform_string(jsx)`` method to transform strings: