Merge pull request #81 from allegro/deprecation-note

added deprecation note

README.md

@@ -2,6 +2,9 @@
 
 [![Build Status](https://github.com/allegro/json-avro-converter/actions/workflows/ci.yml/badge.svg?branch=master)](https://github.com/allegro/json-avro-converter/actions/workflows/ci.yml?query=branch%3Amaster)
 
+> **This project is no longer in active development and is currently in maintenance mode.** 
+We will no longer actively review issues, merge pull-requests, and release new versions. If you are interested in developing it, please fork this repository.
+
 This project is a JSON to Avro conversion tool designed to make migration to Avro easier. It includes a simple command line validator.
 
 ## Motivation