Fix screenshots links to React Native's docs (#3302)

The links were pointing to the wrong documentation sections.

docs/installation-ios.md

@@ -8,11 +8,11 @@
     yarn add react-native-navigation@latest
     ```
 
-2. In Xcode, in Project Navigator (left pane), right-click on the `Libraries` > `Add files to [project name]`. Add `./node_modules/react-native-navigation/ios/ReactNativeNavigation.xcodeproj` ([screenshots](https://facebook.github.io/react-native/docs/linking-libraries-ios.html#step-1))
+2. In Xcode, in Project Navigator (left pane), right-click on the `Libraries` > `Add files to [project name]`. Add `./node_modules/react-native-navigation/ios/ReactNativeNavigation.xcodeproj` ([screenshots](https://facebook.github.io/react-native/docs/0.54/linking-libraries-ios.html#step-1-1))
 
-3. In Xcode, in Project Navigator (left pane), click on your project (top), then click on your *target* row (on the "project and targets list", which is on the left column of the right pane) and select the `Build Phases` tab (right pane). In the `Link Binary With Libraries` section add `libReactNativeNavigation.a` ([screenshots](https://facebook.github.io/react-native/docs/linking-libraries-ios.html#step-2))
+3. In Xcode, in Project Navigator (left pane), click on your project (top), then click on your *target* row (on the "project and targets list", which is on the left column of the right pane) and select the `Build Phases` tab (right pane). In the `Link Binary With Libraries` section add `libReactNativeNavigation.a` ([screenshots](https://facebook.github.io/react-native/docs/0.54/linking-libraries-ios.html#step-2-1))
 
-4. In Xcode, in Project Navigator (left pane), click on your project (top), then click on your *project* row (on the "project and targets list") and select the `Build Settings` tab (right pane). In the `Header Search Paths` section add `$(SRCROOT)/../node_modules/react-native-navigation/ios`. Make sure on the right to mark this new path `recursive` ([screenshots](https://facebook.github.io/react-native/docs/linking-libraries-ios.html#step-3))
+4. In Xcode, in Project Navigator (left pane), click on your project (top), then click on your *project* row (on the "project and targets list") and select the `Build Settings` tab (right pane). In the `Header Search Paths` section add `$(SRCROOT)/../node_modules/react-native-navigation/ios`. Make sure on the right to mark this new path `recursive` ([screenshots](https://facebook.github.io/react-native/docs/0.54/linking-libraries-ios.html#step-3))
 
 5. In Xcode, you will need to edit this file: `AppDelegate.m`.