More instructions on worker loading with create-react-app (cra)

[moritzmhmk]

Is your feature request related to a problem? Please describe.

Instructions on setting pdfjs.GlobalWorkerOptions.workerSrc when using create-react-app (CRA) are rather sparse.

Describe the solution you'd like

I have managed to get around manually copying the files or loading from a CDN (which is not an option for every project) and would like to suggest adding further instructions to the README ;)

Additional information

I use the file-loader via webpack-loader-syntax which is an anti-pattern in CRA because it is not packer agnostic and might break in the future, BUT in the future loading web workers hopefully also works ootb rendering this obsolete...

/* eslint-disable-next-line import/no-webpack-loader-syntax */
import worker from "file-loader!pdfjs-dist/build/pdf.worker.js";
pdfjs.GlobalWorkerOptions.workerSrc = worker;

For typescript support also add this to react-app-env.d.ts

declare module "file-loader!*" {
  const content: string;
  export default content;
}

[wojtekmaj]

Please kindly check React-PDF v5.3.0-beta.2, in which improvements regarding loading PDF.js worker were made.

With these changes you should be able to use Webpack entry file in Create-React-App, without the need of using external CDN for hosting worker.

Let me know what you think in #748!