Remove codelabs submodule and usages (#11264)

The usages are very minimal and the website repo is much smaller and
easier to manage without the huge codelabs repo.

Also fixes some copy formatting and punctuation issues near the updated
code snippets.

.gitignore

@@ -21,3 +21,6 @@ node_modules
 package-lock.json
 pubspec.lock
 tmp/
+
+# Temporary as codelabs used to be a submodule
+examples/codelabs

.gitmodules

@@ -2,6 +2,3 @@
 	path = site-shared
 	url = https://github.com/dart-lang/site-shared
 	branch = main
-[submodule "examples/codelabs"]
-	path = examples/codelabs
-	url = https://github.com/flutter/codelabs

analysis_options.yaml

@@ -1,2 +1,2 @@
 analyzer:
-  exclude: [flutter, site-shared, src, tmp, 'examples/codelabs']
+  exclude: [flutter, site-shared, src, tmp]

examples/accessibility/analysis_options.yaml

@@ -0,0 +1,5 @@
+# Take our settings from the example_utils analysis_options.yaml file.
+# If necessary for a particular example, this file can also include
+# overrides for individual lints.
+
+include: package:example_utils/analysis.yaml

examples/accessibility/lib/main.dart

@@ -0,0 +1,19 @@
+import 'package:flutter/material.dart';
+
+void main() => runApp(const AccessibleApp());
+
+class AccessibleApp extends StatelessWidget {
+  const AccessibleApp({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      title: 'Your accessible app',
+      home: Scaffold(
+        appBar: AppBar(
+          title: const Text('Your accessible app'),
+        ),
+      ),
+    );
+  }
+}

examples/accessibility/pubspec.yaml

@@ -0,0 +1,20 @@
+name: your_accessible_app
+description: A Flutter project to contain accessibility-related code excerpts.
+version: 1.0.0
+publish_to: none
+
+environment:
+  sdk: ^3.5.0
+
+dependencies:
+  flutter:
+    sdk: flutter
+
+dev_dependencies:
+  example_utils:
+    path: ../example_utils
+  flutter_test:
+    sdk: flutter
+
+flutter:
+  uses-material-design: true

examples/accessibility/test/a11y_test.dart

@@ -0,0 +1,26 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:your_accessible_app/main.dart';
+
+void main() {
+  testWidgets('Follows a11y guidelines', (tester) async {
+    final SemanticsHandle handle = tester.ensureSemantics();
+    await tester.pumpWidget(AccessibleApp());
+
+    // Checks that tappable nodes have a minimum size of 48 by 48 pixels
+    // for Android.
+    await expectLater(tester, meetsGuideline(androidTapTargetGuideline));
+
+    // Checks that tappable nodes have a minimum size of 44 by 44 pixels
+    // for iOS.
+    await expectLater(tester, meetsGuideline(iOSTapTargetGuideline));
+
+    // Checks that touch targets with a tap or long press action are labeled.
+    await expectLater(tester, meetsGuideline(labeledTapTargetGuideline));
+
+    // Checks whether semantic nodes meet the minimum text contrast levels.
+    // The recommended text contrast is 3:1 for larger text
+    // (18 point and above regular).
+    await expectLater(tester, meetsGuideline(textContrastGuideline));
+    handle.dispose();
+  });
+}

src/content/cookbook/navigation/set-up-app-links.md

@@ -1,13 +1,10 @@
 ---
 title: Set up app links for Android
-description: How set up universal links for an iOS application built with Flutter
-js:
-  - defer: true
-    url: /assets/js/inject_dartpad.js
+description: >-
+  Learn how to set up app links for an
+  Android application built with Flutter.
 ---
 
-<?code-excerpt path-base="codelabs/deeplink_cookbook"?>
-
 Deep linking is a mechanism for launching an app with a URI.
 This URI contains scheme, host, and path,
 and opens the app to a specific screen.
@@ -21,7 +18,7 @@ Learn more and see a demo at [Validate deep links][].
 
 [Validate deep links]: /tools/devtools/deep-links
 
-A _app link_ is a type of deep link that uses
+An _app link_ is a type of deep link that uses
 `http` or `https` and is exclusive to Android devices.
 
 Setting up app links requires one to own a web domain.
@@ -35,14 +32,14 @@ This example uses the [go_router][] package to handle the routing.
 The Flutter team maintains the `go_router` package.
 It provides a simple API to handle complex routing scenarios.
 
-1. To create a new application, type `flutter create <app-name>`:
+ 1. To create a new application, type `flutter create <app-name>`:
 
-    ```shell
+    ```console
     $ flutter create deeplink_cookbook
     ```
 
-2. To include `go_router` package in your app,
-   add a dependency for `go_router` to the project:
+ 2. To include `go_router` package in your app,
+    add a dependency for `go_router` to the project:
 
     To add the `go_router` package as a dependency,
     run `flutter pub add`:
@@ -51,11 +48,10 @@ It provides a simple API to handle complex routing scenarios.
     $ flutter pub add go_router
     ```
 
-3. To handle the routing,
-   create a `GoRouter` object in the `main.dart` file:
+ 3. To handle the routing,
+    create a `GoRouter` object in the `main.dart` file:
 
-    <?code-excerpt "lib/main.dart"?>
-    ```dartpad title="Flutter GoRouter hands-on example in DartPad" run="true"
+    ```dart title="main.dart"
     import 'package:flutter/material.dart';
     import 'package:go_router/go_router.dart';
     
@@ -84,9 +80,9 @@ It provides a simple API to handle complex routing scenarios.
 
 ## 2. Modify AndroidManifest.xml
 
-1. Open the Flutter project with VS Code or Android Studio. 
-2. Navigate to `android/app/src/main/AndroidManifest.xml` file.
-3. Add the following metadata tag and intent filter inside the
+ 1. Open the Flutter project with VS Code or Android Studio. 
+ 2. Navigate to `android/app/src/main/AndroidManifest.xml` file.
+ 3. Add the following metadata tag and intent filter inside the
    `<activity>` tag with `.MainActivity`.
 
     Replace `example.com` with your own web domain.
@@ -102,14 +98,14 @@ It provides a simple API to handle complex routing scenarios.
     </intent-filter>
     ```
    
-   :::note
-   The metadata tag flutter_deeplinking_enabled opts
-   into Flutter's default deeplink handler.
-   If you are using the third-party plugins,
-   such as [uni_links][], setting this metadata tag will
-   break these plugins. Omit this metadata tag
-   if you prefer to use third-party plugins.
-   :::
+    :::note
+    The metadata tag `flutter_deeplinking_enabled` opts
+    into Flutter's default deeplink handler.
+    If you are using the third-party plugins,
+    such as [uni_links][], setting this metadata tag will
+    break these plugins. Omit this metadata tag
+    if you prefer to use third-party plugins.
+    :::
 
 ## 3. Hosting assetlinks.json file
 
@@ -164,15 +160,15 @@ The hosted file should look similar to this:
 }]
 ```
 
-1. Set the `package_name` value to your Android application ID.
+ 1. Set the `package_name` value to your Android application ID.
 
-2. Set sha256_cert_fingerprints to the value you got
-   from the previous step.
+ 2. Set sha256_cert_fingerprints to the value you got
+    from the previous step.
 
-3. Host the file at a URL that resembles the following:
-   `<webdomain>/.well-known/assetlinks.json`
+ 3.  Host the file at a URL that resembles the following:
+    `<webdomain>/.well-known/assetlinks.json`
 
-4. Verify that your browser can access this file.
+ 4. Verify that your browser can access this file.
 
 :::note
 If you have multiple flavors, you can have many sha256_cert_fingerprint 

src/content/cookbook/navigation/set-up-universal-links.md

@@ -1,13 +1,10 @@
 ---
 title: Set up universal links for iOS
-description: How set up universal links for an iOS application built with Flutter
-js:
-  - defer: true
-    url: /assets/js/inject_dartpad.js
+description: >-
+   Learn how to set up universal links for an
+   iOS application built with Flutter.
 ---
 
-<?code-excerpt path-base="codelabs/deeplink_cookbook"?>
-
 Deep linking allows an app user to launch an app with a URI.
 This URI contains scheme, host, and path,
 and opens the app to a specific screen.
@@ -38,7 +35,7 @@ It provides a simple API to handle complex routing scenarios.
 
 1. To create a new application, type `flutter create <app-name>`.
 
-    ```shell
+    ```console
     $ flutter create deeplink_cookbook
     ```
 
@@ -51,8 +48,7 @@ It provides a simple API to handle complex routing scenarios.
 
 3. To handle the routing, create a `GoRouter` object in the `main.dart` file:
 
-    <?code-excerpt "lib/main.dart"?>
-    ```dartpad title="Flutter GoRouter hands-on example in DartPad" run="true"
+    ```dart title="main.dart"
     import 'package:flutter/material.dart';
     import 'package:go_router/go_router.dart';
     
@@ -90,8 +86,7 @@ It provides a simple API to handle complex routing scenarios.
 
 1. In the Xcode Navigator, expand **Runner** then click **Info**.
 
-   <img
-       src="/assets/images/docs/cookbook/set-up-universal-links-info-plist.png"
+   <img src="/assets/images/docs/cookbook/set-up-universal-links-info-plist.png"
        alt="Xcode info.Plist screenshot"
        width="100%" />
 
@@ -111,7 +106,7 @@ It provides a simple API to handle complex routing scenarios.
 
    <img
       src="/assets/images/docs/cookbook/set-up-universal-links-flutterdeeplinkingenabled.png"
-      alt="flutter deeplinking enabled screenshot"
+      alt="Screenshot of FlutterDeepLinkingEnabled value set to YES."
       width="100%" />
 
    :::note
@@ -162,7 +157,7 @@ capability. To add associated domains, choose the IDE tab.
 {% endtab %}
 {% tab "Other editors" %}
 
-1. Open the `ios/Runner/Runner.entitlements` XML file in your preferred IDE.
+1. Open the `ios/Runner/Runner.entitlements` XML file in your preferred editor.
 
 1. Add an associated domain inside the `<dict>` tag.
 
@@ -181,8 +176,8 @@ capability. To add associated domains, choose the IDE tab.
 
 1. Save the `ios/Runner/Runner.entitlements` file.
 
-To check that the associated domains you created are available, perform
-the following steps.
+To check that the associated domains you created are available,
+perform the following steps:
 
 1. Launch Xcode if necessary.
 
@@ -207,8 +202,10 @@ You have finished configuring the application for deep linking.
 ## Associate your app with your web domain
 
 You need to host an `apple-app-site-association` file in the web domain.
-This file tells the mobile browser which iOS application to open instead of the browser.
-To create the file, find the `appID` of the Flutter app you created in the previous section.
+This file tells the mobile browser which
+iOS application to open instead of the browser.
+To create the file, find the `appID` of the Flutter app you
+created in the previous section.
 
 ### Locate components of the `appID`
 
@@ -273,17 +270,16 @@ this file should resemble the following content:
 1. Verify that your browser can access this file.
 
 :::note
-If you have more than one scheme/flavor, you can add more than one appID 
-into appIDs fields
+If you have more than one scheme/flavor, you can
+add more than one `appID` into the `appIDs` field.
 :::
 
 ## Test the universal link
 
 Test a universal link using a physical iOS device or the Simulator.
 
 :::note
-It might take up to 24 hours before Apple's
-[Content Delivery Network](https://en.wikipedia.org/wiki/Content_delivery_network) (CDN)
+It might take up to 24 hours before Apple's [Content Delivery Network][] (CDN)
 requests the `apple-app-site-association` (AASA) file from your web domain.
 Until the CDN requests the file, the universal link won't work.
 To bypass Apple's CDN, check out the [alternate mode section][].
@@ -321,6 +317,8 @@ To bypass Apple's CDN, check out the [alternate mode section][].
       alt="Deeplinked Simulator screenshot"
       width="50%" />
 
+[Content Delivery Network]: https://en.wikipedia.org/wiki/Content_delivery_network
+
 ## Find the source code
 
 You can find the source code for the [deeplink_cookbook][]