MBX-3120: Updating README.md (#68)

 Update README.md

Author: Robalim

.github/workflows/publish.yml

@@ -140,3 +140,6 @@ jobs:
           release_name: mindbox v${{ env.VERSION }}
           draft: false
           prerelease: false
+
+      - name: Version Upgrade
+        run: ./version-update.sh "${{ env.VERSION }}"

README.md

@@ -0,0 +1,47 @@
+[![PubDev](https://img.shields.io/pub/v/mindbox)](https://pub.dev/packages/mindbox)
+
+# Mindbox SDK for Flutter
+
+The Mindbox SDK allows you to integrate mobile push-notifications, in-app messages and client events into your Flutter projects.
+
+## Getting Started
+
+These instructions will help you integrate the Mindbox SDK into your Flutter app.
+
+### Installation
+
+To integrate Mindbox SDK into your Flutter app, follow the installation process detailed [here](https://developers.mindbox.ru/docs/add-sdk-flutter). Here is an overview:
+
+Add Mindbox's dependency to your pubspec.yaml file:
+```markdown
+   dependencies:
+flutter:
+sdk: flutter
+mindbox: ^2.8.2
+```
+
+### Initialization
+
+Initialize the Mindbox SDK in your Activity or Application class. Check documentation [here](https://developers.mindbox.ru/docs/sdk-initialization-flutter) for more details.
+
+### Operations
+
+Learn how to send events to Mindbox. Create a new Operation class object and set the respective parameters. Check the [documentation](https://developers.mindbox.ru/docs/integration-actions-flutter) for more details.
+
+### Push Notifications
+
+Mindbox SDK helps handle push notifications. Configuration and usage instructions can be found in the SDK documentation [here](https://developers.mindbox.ru/docs/firebase-send-push-notifications-flutter),  [here](https://developers.mindbox.ru/docs/huawei-send-push-notifications-flutter) and [here](https://developers.mindbox.ru/docs/ios-send-push-notifications-flutter).
+
+## Troubleshooting
+
+Refer to the [Example of integration(IOS)](https://github.com/mindbox-cloud/flutter-sdk/tree/develop/mindbox_ios/example) or [Example of integration(Android)](https://github.com/mindbox-cloud/flutter-sdk/tree/develop/mindbox_android/example) in case of any issues.
+
+## Further Help
+
+Reach out to us for further help and we'll be glad to assist.
+
+## License
+
+The library is available as open source under the terms of the [License](https://github.com/mindbox-cloud/android-sdk/blob/develop/LICENSE.md).
+
+For a better understanding of this content, please familiarize yourself with the Mindbox [Flutter SDK](https://developers.mindbox.ru/docs/flutter-sdk-integration) documentation.

version-update.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+VERSION=$1
+sed -i -e "s|mindbox: ^[0-9].[0-9].[0-9]|mindbox: ^${VERSION}|" README.md