fix: update Node.js version requirement in README to match package.json (#2596)

Co-authored-by: Byron Gravenorst <50852695+bgravenorst@users.noreply.github.com>

Author: subhamkumarr

README.md

@@ -11,7 +11,7 @@ Build the documentation site locally using the following steps.
 
 ### Prerequisites
 
-- [Node.js](https://nodejs.org/) version 18+
+- [Node.js](https://nodejs.org/) version 20.x
 - [Git](https://git-scm.com/)
 
 ### Steps