Document how to use zkApps with create-react-app

[mitschabaude]

Quoting a great write-up shared by from Gordon Freeman on discord:

1. npx create-react-app --template typescript

2. npm run eject

3. add the following line to the config/webpack.config.json in the return statement
   experiments: { topLevelAwait: true },
   (on my setup it is before the line target: ['browserslist'],)

4. go to your zkapp project and type: npm link

5. go to your react app and type: npm link
   5.1. make sure that the name matches the name in your zkapp package.json
   5.2 if there is a type stuff error during import use this // @ts-ignore right before the import statement in your react app
   // @ts-ignore
   import { Multisignature } from 'zkapp-multisign'
   https://stackoverflow.com/questions/64732623/react-typescript-cannot-find-module-or-its-corresponding-type-declaration

6. if there is an import error you might have to set the file extension of your zkapp in
   /build/src/index.js manually (like this: import { Multisignature } from './Multisignature.js';) -- .js is the important part
   6.1 Don't forget to add this file extension after every build of your zkapp

[jasongitmail]

Closing as an old issue.

We built support for NextJS into the zkApp CLI (via zk project <name> --ui next) and have chosen to focus our efforts and guide devs down NextJS path b/c it's a better, modern framework, a CRA workflow that requires using 'eject' will leave devs with a maintainence headache long term, etc.