[go_router] docs: replace out dated initialRoute to initialLocation (flutter#7147)

����Updated the outdated configurations in [upgrading.md](flutter/packages@main...unliar:packages:main#diff-0acd78ed04ed5af73daeb7496126c67bd4997e3068806c90d0385f323af20e7b).

Author: unliar

packages/go_router/CHANGELOG.md

@@ -1,6 +1,7 @@
-## NEXT
+## 14.2.4
 
-* Updates minimum supported SDK version to Flutter 3.19/Dart 3.3.
+- Updates minimum supported SDK version to Flutter 3.19/Dart 3.3.
+- Fix GoRouter configuration in `upgrading.md`
 
 ## 14.2.3
 

packages/go_router/doc/upgrading.md

@@ -3,6 +3,7 @@ home screen and creating a GoRoute for each screen you would like to be
 deep-linkable.
 
 # Upgrade an app that uses Navigator
+
 To upgrade an app that is already using the Navigator for routing, start with
 a single route for the home screen:
 
@@ -37,6 +38,7 @@ aren't deep-linkable. You can gradually add more routes to the GoRouter
 configuration.
 
 # Upgrade an app that uses named routes
+
 An app that uses named routes can be migrated to go_router by changing each
 entry in the map to a GoRoute object and changing any calls to
 `Navigator.of(context).pushNamed` to `context.go()`.
@@ -57,7 +59,7 @@ Then the GoRouter configuration would look like this:
 
 ```dart
 GoRouter(
-  initialRoute: '/details',
+  initialLocation: '/details',
   routes: [
     GoRoute(
       path: '/',

packages/go_router/pubspec.yaml

@@ -1,7 +1,7 @@
 name: go_router
 description: A declarative router for Flutter based on Navigation 2 supporting
   deep linking, data-driven routes and more
-version: 14.2.3
+version: 14.2.4
 repository: https://github.com/flutter/packages/tree/main/packages/go_router
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+go_router%22