readme: archive project - suggest alternatives

Signed-off-by: Practicalli Johnny <250870+practicalli-johnny@users.noreply.github.com>

README.md

@@ -1,8 +1,15 @@
-# Clojure development with Atom & ProtoREPL
+# Archived project: Clojure development with Atom & ProtoREPL
 
-An introduction to developing Clojure applications using Atom, specifically based on the ProtoREPL plugin.
+**Atom editor project has was [sunset in January 2023](https://github.blog/2022-06-08-sunsetting-atom/) so this guide is no longer relevant**
+
+[Pulsar](https://pulsar-edit.dev/) is a community led project based on the Atom.io editor and could be a promising alternative.
+
+[Practicalli Cloure - Editors](https://practical.li/clojure/clojure-editors/) provides an overview of editors with Clojure programming support.
 
-[![Join the conversation on Gitter](images/gitter-chat-badge-practicalli.png)](https://gitter.im/practicalli/chat?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
+
+--- 
+
+An introduction to developing Clojure applications using Atom, specifically based on the ProtoREPL plugin.
 
 This workshop will cover the following topics: