Add retirement notice to the README.md

Author: tanersener

README.md

@@ -1,5 +1,17 @@
 # FFmpegKit ![GitHub release](https://img.shields.io/badge/release-v6.0-blue.svg) ![Maven Central](https://img.shields.io/maven-central/v/com.arthenica/ffmpeg-kit-min) ![CocoaPods](https://img.shields.io/cocoapods/v/ffmpeg-kit-ios-min) ![pub](https://img.shields.io/pub/v/ffmpeg_kit_flutter.svg) ![npm](https://img.shields.io/npm/v/ffmpeg-kit-react-native.svg)
 
+## Notice
+FFmpegKit has been officially retired. There will be no further `ffmpeg-kit` releases. 
+
+All previously released `ffmpeg-kit` binaries will be removed according to the following schedule.
+
+| FFmpegKit Version |  Available Until   |
+|:-----------------:|:------------------:|
+|   Less than 6.0   | February 1st, 2025 |
+|        6.0        |  April 1st, 2025   |
+
+Thank you for your support and interest in this project.
+
 <img src="https://github.com/arthenica/ffmpeg-kit/blob/main/docs/assets/ffmpeg-kit-icon-v9.png" width="240">
 
 `FFmpegKit` is a collection of tools to use `FFmpeg`<sup>1</sup> in `Android`, `iOS`, `Linux`, `macOS`, `tvOS`, `Flutter` and `React Native` applications.