Add documentation for using create-react-app with yarn pnp

### Is your proposal related to a problem?

Documentation request for uding create-react-app with yarn 2 pnp.

### Describe the solution you'd like

To use create-react-app with yarn 2 pnp.

(Describe your proposed solution here.)

Document solution for using create-react-app with yarn 2 pnp


thanks