docs: update minimum node version in readme (#1691)

* chore: update minimum node version in readme

* Update README.md

---------

Co-authored-by: Keith Cirkel <[email protected]>

Author: SuperchupuDev

README.md

@@ -20,7 +20,7 @@
   <a href="https://www.npmjs.com/package/chai">
     <img
       alt="node:?"
-      src="https://img.shields.io/badge/node-%3E=4.0-blue.svg?style=flat-square"
+      src="https://img.shields.io/badge/node-%3E=18.0-blue.svg?style=flat-square"
     />
   </a>
   <br/>