docs: fix readme. (#162)

* docs: fix readme.

* docs: update note

---------

Co-authored-by: Arjun Vegda <14841132+arjunvegda@users.noreply.github.com>

Author: bigbossx

README.md

@@ -30,7 +30,7 @@
 
 ## ☝️ Prerequisites
 
-- Jotai version `>=1.11.0` (highly recommended to use `2.x.x`)
+- Jotai version `>=2.1.0.`
 - React version `>=17.0.0`
 
 ## 📦 Setup