[Docs] Update docs for "Running on Device"

[jefflau]

Hi there,

I'm new to React Native and I was having problems with Running on Device yesterday on iOS. I was following this section of the docs:

https://facebook.github.io/react-native/docs/running-on-device-ios.html

I realised after I was using 0.28 and in the latest stable release 0.29 you don't have to change localhost to your IP Address on the network as stated in these docs.. In fact I couldn't even find localhost in the AppDelegate.m so this part no longer seems relevant and may be confusing to people reading it.

[charpeni]

@facebook-github-bot label Documentation

[inetfuture]

I'm curious, how does it work now?

[charpeni]

@inetfuture You can refer to 8c29a52

[inetfuture]

get it, thanks