Changing a note to a warning and changing master -> main (#11593)

As it says. Also altered some formatting.

Fixes #11485

src/content/add-to-app/android/add-flutter-view.md

@@ -38,40 +38,57 @@ for some of the cells in a RecycleView list of cards as seen in the gif above.
 
 ## General approach
 
-The general gist of the FlutterView-level integration is that you must recreate
-the various interactions between your Activity, the [FlutterView]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterView.html)
-and the [FlutterEngine]({{site.api}}/javadoc/io/flutter/embedding/engine/FlutterEngine.html)
-present in the [FlutterActivityAndFragmentDelegate](https://cs.opensource.google/flutter/engine/+/master:shell/platform/android/io/flutter/embedding/android/FlutterActivityAndFragmentDelegate.java)
-in your own application's code. The connections made in the [FlutterActivityAndFragmentDelegate](https://cs.opensource.google/flutter/engine/+/master:shell/platform/android/io/flutter/embedding/android/FlutterActivityAndFragmentDelegate.java)
-are done automatically when using a [FlutterActivity]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterActivity.html)
-or a [FlutterFragment]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterFragment.html),
-but since the [FlutterView]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterView.html)
-in this case is being added to an Activity or Fragment in your application,
-you must recreate the connections manually. Otherwise, the [FlutterView]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterView.html)
-will not render anything or have other missing functionalities.
-
-A sample [FlutterViewEngine]({{site.repo.samples}}/blob/main/add_to_app/android_view/android_view/app/src/main/java/dev/flutter/example/androidView/FlutterViewEngine.kt)
+The general gist of the FlutterView-level integration is that you
+must recreate the various interactions between your Activity, the
+[`FlutterView`]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterView.html)
+and the
+[`FlutterEngine`]({{site.api}}/javadoc/io/flutter/embedding/engine/FlutterEngine.html)
+present in the [`FlutterActivityAndFragmentDelegate`](https://cs.opensource.google/flutter/engine/+/main:shell/platform/android/io/flutter/embedding/android/FlutterActivityAndFragmentDelegate.java)
+in your own application's code.
+The connections made in the
+[`FlutterActivityAndFragmentDelegate`](https://cs.opensource.google/flutter/engine/+/main:shell/platform/android/io/flutter/embedding/android/FlutterActivityAndFragmentDelegate.java)
+are done automatically when using a
+[`FlutterActivity`]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterActivity.html)
+or a
+[`FlutterFragment`]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterFragment.html),
+but since the [`FlutterView`]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterView.html)
+in this case is being added to an `Activity` or `Fragment` in your application,
+you must recreate the connections manually.
+Otherwise, the [`FlutterView`]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterView.html)
+won't render anything or have other missing functionalities.
+
+A sample
+[`FlutterViewEngine`]({{site.repo.samples}}/blob/main/add_to_app/android_view/android_view/app/src/main/java/dev/flutter/example/androidView/FlutterViewEngine.kt)
 class shows one such possible implementation of an application-specific
-connection between an Activity, a [FlutterView]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterView.html)
+connection between an `Activity`, a
+[`FlutterView`]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterView.html)
 and a [FlutterEngine]({{site.api}}/javadoc/io/flutter/embedding/engine/FlutterEngine.html).
 
 ### APIs to implement
 
-The absolute minimum implementation needed for Flutter to draw anything at all
-is to:
-
-- Call [attachToFlutterEngine]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterView.html#attachToFlutterEngine-io.flutter.embedding.engine.FlutterEngine-) when the
-  [FlutterView]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterView.html)
-  is added to a resumed Activity's view hierarchy and is visible; and
-- Call [appIsResumed]({{site.api}}/javadoc/io/flutter/embedding/engine/systemchannels/LifecycleChannel.html#appIsResumed--) on the [FlutterEngine]({{site.api}}/javadoc/io/flutter/embedding/engine/FlutterEngine.html)'s
-  `lifecycleChannel` field when the Activity hosting the [FlutterView]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterView.html)
+The absolute minimum implementation needed for Flutter
+to draw anything at all is to:
+
+* Call [`attachToFlutterEngine`]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterView.html#attachToFlutterEngine-io.flutter.embedding.engine.FlutterEngine-)
+  when the
+  [`FlutterView`]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterView.html)
+  is added to a resumed `Activity`'s view hierarchy and is visible; and
+* Call [`appIsResumed`]({{site.api}}/javadoc/io/flutter/embedding/engine/systemchannels/LifecycleChannel.html#appIsResumed--)
+  on the [`FlutterEngine`]({{site.api}}/javadoc/io/flutter/embedding/engine/FlutterEngine.html)'s
+  `lifecycleChannel` field when the `Activity` hosting the
+  [`FlutterView`]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterView.html)
   is visible.
 
-The reverse [detachFromFlutterEngine]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterView.html#detachFromFlutterEngine--) and other lifecycle methods on the [LifecycleChannel]({{site.api}}/javadoc/io/flutter/embedding/engine/systemchannels/LifecycleChannel.html)
-class must also be called to not leak resources when the FlutterView or Activity
-is no longer visible.
-
-In addition, see the remaining implementation in the [FlutterViewEngine]({{site.repo.samples}}/blob/main/add_to_app/android_view/android_view/app/src/main/java/dev/flutter/example/androidView/FlutterViewEngine.kt)
-demo class or in the [FlutterActivityAndFragmentDelegate](https://cs.opensource.google/flutter/engine/+/master:shell/platform/android/io/flutter/embedding/android/FlutterActivityAndFragmentDelegate.java)
-to ensure a correct functioning of other features such as clipboards, system
-UI overlay, plugins etc.
+The reverse
+[`detachFromFlutterEngine`]({{site.api}}/javadoc/io/flutter/embedding/android/FlutterView.html#detachFromFlutterEngine--)
+and other lifecycle methods on the
+[`LifecycleChannel`]({{site.api}}/javadoc/io/flutter/embedding/engine/systemchannels/LifecycleChannel.html)
+class must also be called to not leak resources when the
+`FlutterView` or `Activity` is no longer visible.
+
+In addition, see the remaining implementation in the
+[`FlutterViewEngine`]({{site.repo.samples}}/blob/main/add_to_app/android_view/android_view/app/src/main/java/dev/flutter/example/androidView/FlutterViewEngine.kt)
+demo class or in the
+[`FlutterActivityAndFragmentDelegate`](https://cs.opensource.google/flutter/engine/+/main:shell/platform/android/io/flutter/embedding/android/FlutterActivityAndFragmentDelegate.java)
+to ensure a correct functioning of other features such as clipboards,
+system UI overlay, plugins, and so on.

src/content/add-to-app/android/project-setup.md

@@ -431,10 +431,12 @@ val filePath = settingsDir.parentFile.toString() + "/flutter_module/.android/inc
 apply(from = File(filePath))
 ```
 
-:::note
-The ability to invoke `include_flutter.groovy` from Kotlin code requires Flutter 3.27.
-To determine your current Flutter version, run `flutter --version`. If it is not
-at least version 3.27, consider changing to either the `master` or `beta` channels.
+:::warning
+The ability to invoke `include_flutter.groovy` from Kotlin code
+requires Flutter 3.27.
+To determine your current Flutter version,
+run `flutter --version`. If it isn't at least version 3.27,
+consider changing to either the `main` or `beta` channels.
 :::
 
 If you are using Groovy, apply the following changes:

src/content/add-to-app/index.md

@@ -201,7 +201,7 @@ Web limitations:
 [`FlutterActivity`]: {{site.api}}/javadoc/io/flutter/embedding/android/FlutterActivity.html
 [java-engine]: {{site.api}}/javadoc/io/flutter/embedding/engine/FlutterEngine.html
 [ios-engine]: {{site.api}}/ios-embedder/interface_flutter_engine.html
-[FlutterFire]: {{site.github}}/firebase/flutterfire/tree/master/packages
+[FlutterFire]: {{site.github}}/firebase/flutterfire/tree/main/packages
 [`FlutterFragment`]: {{site.api}}/javadoc/io/flutter/embedding/android/FlutterFragment.html
 [`FlutterPlugin`]: {{site.api}}/javadoc/io/flutter/embedding/engine/plugins/FlutterPlugin.html
 [`FlutterViewController`]: {{site.api}}/ios-embedder/interface_flutter_view_controller.html

src/content/add-to-app/multiple-flutters.md

@@ -90,5 +90,5 @@ on both Android and iOS on [GitHub][].
 [Issue 72009]: {{site.repo.flutter}}/issues/72009
 [Pigeon]: {{site.pub}}/packages/pigeon
 [platform channels]: /platform-integration/platform-channels
-[Android API]: https://cs.opensource.google/flutter/engine/+/master:shell/platform/android/io/flutter/embedding/engine/FlutterEngineGroup.java
-[iOS API]: https://cs.opensource.google/flutter/engine/+/master:shell/platform/darwin/ios/framework/Headers/FlutterEngineGroup.h
+[Android API]: https://cs.opensource.google/flutter/engine/+/main:shell/platform/android/io/flutter/embedding/engine/FlutterEngineGroup.java
+[iOS API]: https://cs.opensource.google/flutter/engine/+/main:shell/platform/darwin/ios/framework/Headers/FlutterEngineGroup.h

src/content/add-to-app/performance.md

@@ -207,7 +207,7 @@ For performance details on creating more than one `FlutterEngine`,
 see [multiple Flutters][].
 
 [android-engine]: {{site.api}}/javadoc/io/flutter/embedding/engine/FlutterEngine.html
-[auxiliary threads]: {{site.repo.flutter}}/blob/master/docs/about/The-Engine-architecture.md#threading
+[auxiliary threads]: {{site.repo.flutter}}/blob/main/docs/about/The-Engine-architecture.md#threading
 [CAEAGLLayer]: {{site.apple-dev}}/documentation/quartzcore/caeagllayer
 [CAMetalLayer]: {{site.apple-dev}}/documentation/quartzcore/cametallayer
 [Dart `Isolate`]: {{site.dart.api}}/dart-isolate/Isolate-class.html