update readme

Author: rmosolgo

README.md

@@ -194,7 +194,7 @@ MyApp::Application.configure do
   config.react.server_renderer_timeout    ||= 20 # seconds
   config.react.server_renderer = React::ServerRendering::SprocketsRenderer
   config.react.server_renderer_options = {
-    files: ["react.js", "components.js"], # files to load for prerendering
+    files: ["react-server.js", "components.js"], # files to load for prerendering
     replay_console: true,                 # if true, console.* will be replayed client-side
   }
 end