fix: add missing RCTLinkingManager fallback in RN 0.77+ setup and example app (#1115)

Author: victoreronmosele

.changeset/rich-avocados-complain.md

@@ -0,0 +1,5 @@
+---
+'react-native-app-auth': patch
+---
+
+Add missing RCTLinkingManager fallback for non-auth urls in iOS AppDelegate setup docs and example

docs/docs/introduction.md

@@ -183,7 +183,7 @@ class AppDelegate: UIResponder, UIApplicationDelegate,
         return true
       }
     }
-    return false
+    return RCTLinkingManager.application(app, open: url, options: options)
   }
 }
 ```

examples/demo/ios/Example/AppDelegate.swift

@@ -53,7 +53,7 @@ class AppDelegate: UIResponder, UIApplicationDelegate,
         return true
       }
     }
-    return false
+    return RCTLinkingManager.application(app, open: url, options: options)
   }
 
   func application(