Update Debugging.md

Summary:Fixes facebook#7131

I believe it's easier if we just link to this file so it's less confusing what to edit actually. I was originally thinking about linking to specific line, but that will be hard to keep in sync.
Closes facebook#7139

Differential Revision: D3212912

Pulled By: mkonicek

fb-gh-sync-id: 4f272d8bc922b273b961707d9ebf18a3efda31be
fbshipit-source-id: 4f272d8bc922b273b961707d9ebf18a3efda31be

docs/Debugging.md

@@ -49,7 +49,7 @@ In Chrome, press `⌘ + option + i` or select `View` → `Developer` → `Develo
 
 To debug on a real device:
 
-1. On iOS - open the file `RCTWebSocketExecutor.m` and change `localhost` to the IP address of your computer. Shake the device to open the development menu with the option to start debugging.
+1. On iOS - open the file [`RCTWebSocketExecutor.m`](https://github.com/facebook/react-native/blob/master/Libraries/WebSocket/RCTWebSocketExecutor.m) and change `localhost` to the IP address of your computer. Shake the device to open the development menu with the option to start debugging.
 2. On Android, if you're running Android 5.0+ device connected via USB you can use `adb` command line tool to setup port forwarding from the device to your computer. For that run: `adb reverse tcp:8081 tcp:8081` (see [this link](http://developer.android.com/tools/help/adb.html) for help on `adb` command). Alternatively, you can [open dev menu](#debugging-react-native-apps) on the device and select `Dev Settings`, then update `Debug server host for device` setting to the IP address of your computer.
 
 ### Custom JavaScript debugger