docs: update ios-guide.md (#1002)

* Update ios-guide.md

I tried to clarify the wording for the `AppDelegate.m` method for the URL scheme. It's up to you to accept or not ;)

* Update ios-guide.md

Removing a wrong sentence.

docs/ios-guide.md

@@ -54,7 +54,7 @@ Because only one `openURL` method can be defined, if you have multiple listeners
 
 - Open `AppDelegate.m`
 - Add an import: `#import <RNGoogleSignin/RNGoogleSignin.h>` (if this one will not work try `#import "RNGoogleSignin.h"`). If this file cannot be found, you need to modify your header search paths so Xcode can find headers of `react-native-google-signin`. For example, when using the non-cocoapods installation, make sure that `$(SRCROOT)/../node_modules/@react-native-google-signin/google-signin/ios` is included in your target's header search paths.
-- Add a method to respond to the URL scheme (this is just an example of what the code can look like if you're using both `FBSDKApplicationDelegate` and `RNGoogleSignin`):
+- Add a method to respond to the URL scheme. This is just an example of a method that you can add at the bottom of your file if you're using both `FBSDKApplicationDelegate` and `RNGoogleSignin` :
 
 ```objc
 // AppDelegate.m