Add support for React & Node 18 (as easy as adding startTransition() on each setState)

Summary:

Current react modal doesn't work with latest version of React + Node v18

Steps to reproduce:

1. Use react-modal with latest React's and Node v18

Expected behavior:

Should work normally

Example of issue:

Breaks with the following error message:

Solution:

Simply add startTransition() wrapping each of the calls for setting the state. startTransition(() => setState("something))