Added FAQ about testing in debug mode

Author: max-mironov

README.md

@@ -352,6 +352,7 @@ Now you'll be able to see CodePush logs in either debug or release mode, on both
 | Update not being discovered | Double-check that the version of your running app (e.g. `1.0.0`) matches the version you specified when releasing the update to CodePush. Additionally, make sure that you are releasing to the same deployment that your app is configured to sync with. |
 | Update not being displayed after restart | If you're not calling `sync` on app start (e.g. within `componentDidMount` of your root component), then you need to explicitly call `notifyApplicationReady` on app start, otherwise, the plugin will think your update failed and roll it back. |
 | I've released an update for iOS but my Android app also shows an update and it breaks it | Be sure you have different deployment keys for each platform in order to receive updates correctly |
+| I've released new update but changes are not reflected | Be sure that you are running app in modes other than Debug. In Debug mode, React Native app always downloads JS bundle generated by packager, so JS bundle downloaded by CodePush does not apply.
 | Images dissappear after installing CodePush update | If your app is using the React Native assets system to load images (i.e. the `require(./foo.png)` syntax), then you **MUST** release your assets along with your JS bundle to CodePush. Follow [these instructions](#releasing-updates-javascript--images) to see how to do this. |
 | No JS bundle is being found when running your app against the iOS simulator | By default, React Native doesn't generate your JS bundle when running against the simulator. Therefore, if you're using `[CodePush bundleURL]`, and targetting the iOS simulator, you may be getting a `nil` result. This issue will be fixed in RN 0.22.0, but only for release builds. You can unblock this scenario right now by making [this change](https://github.com/facebook/react-native/commit/9ae3714f4bebdd2bcab4d7fdbf23acebdc5ed2ba) locally.