add flutter kotlin instrumentation doc

docs/guides/flutter-mobile-observability.md

@@ -97,7 +97,7 @@ hand-build. It is published on
 
 ```yaml title="pubspec.yaml"
 dependencies:
-  scout_flutter: ^0.1.23
+  scout_flutter: ^0.2.0
 ```
 
 Then install:

docs/instrument/mobile/flutter.md

@@ -95,7 +95,7 @@ Add it to your `pubspec.yaml`:
 ```yaml
 # pubspec.yaml
 dependencies:
-  scout_flutter: ^0.1.23
+  scout_flutter: ^0.2.0
 ```
 
 Or:
@@ -104,6 +104,16 @@ Or:
 flutter pub add scout_flutter
 ```
 
+:::note What changed in 0.2.0
+The native engine now starts alongside the Flutter SDK on both platforms. This
+is additive for a pure-Flutter app: Flutter telemetry is unchanged, and you also
+get native crash capture and CPU/memory vitals under a native scope
+(`base14.scout.android` or `base14.scout.ios`) next to `base14.scout.flutter`.
+
+The same mechanism lets a native host app share one session with embedded
+Flutter. See [Hybrid (Native + Flutter)](./hybrid.md).
+:::
+
 ### iOS — CocoaPods install
 
 The first build after adding scout_flutter triggers a pod install for