Add VAD example for Dart API (#996)

sherpa-onnx/flutter/pubspec.yaml

@@ -1,17 +1,24 @@
 name: sherpa_onnx
+
 description: >
-  Dart bindings for sherpa-onnx.
-repository: https://github.com/k2-fsa/sherpa-onnx/tree/main/sherpa-onnx/flutter
+  Speech recognition, speech synthesis, and speaker recognition using next-gen Kaldi
+  with onnxruntime without Internet connection.
+
+repository: https://github.com/k2-fsa/sherpa-onnx/tree/master/sherpa-onnx/flutter
+
+issue_tracker: https://github.com/k2-fsa/sherpa-onnx/issues
+documentation: https://k2-fsa.github.io/sherpa/onnx/
+
 topics:
-  - speech-to-text
-  - text-to-speech
+  - speech-recognition
+  - speech-synthesis
   - speaker-identification
-  - spoken-language-identification
   - audio-tagging
   - voice-activity-detection
 
 # remember to change the version in macos/sherpa_onnx.podspec
-version: 0.0.1
+version: 0.0.2
+
 homepage: https://github.com/k2-fsa/sherpa-onnx
 
 environment:
@@ -22,30 +29,14 @@ dependencies:
   ffi: ^2.1.0
   flutter:
     sdk: flutter
-  plugin_platform_interface: ^2.0.2
 
 dev_dependencies:
   flutter_test:
     sdk: flutter
   flutter_lints: ^3.0.0
 
-# For information on the generic Dart part of this file, see the
-# following page: https://dart.dev/tools/pub/pubspec
-
 # The following section is specific to Flutter packages.
 flutter:
-  # This section identifies this Flutter project as a plugin project.
-  # The 'pluginClass' specifies the class (in Java, Kotlin, Swift, Objective-C, etc.)
-  # which should be registered in the plugin registry. This is required for
-  # using method channels.
-  # The Android 'package' specifies package in which the registered class is.
-  # This is required for using method channels on Android.
-  # The 'ffiPlugin' specifies that native code should be built and bundled.
-  # This is required for using `dart:ffi`.
-  # All these are used by the tooling to maintain consistency when
-  # adding or updating assets for this project.
-  #
-  # Please refer to README.md for a detailed explanation.
   plugin:
     platforms:
       macos:
@@ -54,34 +45,3 @@ flutter:
         ffiPlugin: true
       linux:
         ffiPlugin: true
-
-  # To add assets to your plugin package, add an assets section, like this:
-  # assets:
-  #   - images/a_dot_burr.jpeg
-  #   - images/a_dot_ham.jpeg
-  #
-  # For details regarding assets in packages, see
-  # https://flutter.dev/assets-and-images/#from-packages
-  #
-  # An image asset can refer to one or more resolution-specific "variants", see
-  # https://flutter.dev/assets-and-images/#resolution-aware
-
-  # To add custom fonts to your plugin package, add a fonts section here,
-  # in this "flutter" section. Each entry in this list should have a
-  # "family" key with the font family name, and a "fonts" key with a
-  # list giving the asset and other descriptors for the font. For
-  # example:
-  # fonts:
-  #   - family: Schyler
-  #     fonts:
-  #       - asset: fonts/Schyler-Regular.ttf
-  #       - asset: fonts/Schyler-Italic.ttf
-  #         style: italic
-  #   - family: Trajan Pro
-  #     fonts:
-  #       - asset: fonts/TrajanPro.ttf
-  #       - asset: fonts/TrajanPro_Bold.ttf
-  #         weight: 700
-  #
-  # For details regarding fonts in packages, see
-  # https://flutter.dev/custom-fonts/#from-packages