Fix grammar in the "Running on a device" docs

Summary:
The wording had some grammar issues. The instructions were also not as precise as they could be.

Verified on Xcode 8.2.1.
Closes #13093

Differential Revision: D4763071

Pulled By: hramos

fbshipit-source-id: fe9da098f0e457efba4712db704692f6f4857624

docs/RunningOnDevice.md

@@ -56,11 +56,11 @@ Installing an app on an iOS device requires a Mac, an Apple ID, and a USB cable.
 
 <block class="mac ios" />
 
-Connect your device to your Mac via USB, then open Xcode. Navigate into `ios` folder of your project and open the file ending .xcodeproj inside it. In the project navigator, choose your device from the Product > Destination toolbar menu. Xcode will then register your device for development.
+Connect your device to your Mac using a USB cable. Navigate to the `ios` folder in your project, then open the `.xcodeproj` file within it using Xcode. Open the "Product" menu from the menubar, then go to "Destination". Look for and select your device from the list. Xcode will then register your device for development.
 
-> If you run into any issues, please take a look at Apple's [Launching Your App on a Device docs](https://developer.apple.com/library/content/documentation/IDEs/Conceptual/AppDistributionGuide/LaunchingYourApponDevices/LaunchingYourApponDevices.html#//apple_ref/doc/uid/TP40012582-CH27-SW4).
+If everything is set up correctly, your device will be listed as the build target in the Xcode toolbar. You can now press the **Build and run** button or select "Run" from the "Product" menu. Your app will launch on your device shortly.
 
-Finally, select your phone as the build target and press **Build and run**.
+> If you run into any issues, please take a look at Apple's [Launching Your App on a Device](https://developer.apple.com/library/content/documentation/IDEs/Conceptual/AppDistributionGuide/LaunchingYourApponDevices/LaunchingYourApponDevices.html#//apple_ref/doc/uid/TP40012582-CH27-SW4) docs.
 
 <block class="mac windows linux android" />