docs: deprecate message (#309)

Author: hacdias

Diff for: README.md

@@ -1,3 +1,9 @@
+## ⚠️ This package is no longer being maintained ⚠️
+
+Please use [`kubo/client/rpc`](github.com/ipfs/kubo/client/rpc) instead. In rare case the new library does not offer a feature this one does, fill issue in Kubo, or better, submit a PR that adds it to `kubo/client/rpc`.
+
+For more details about the decision, see https://github.com/ipfs/kubo/issues/9124.
+
 # go-ipfs-api
 
 [![](https://img.shields.io/badge/made%20by-Protocol%20Labs-blue.svg?style=flat-square)](https://protocol.ai)