Broken link in README.md, the link to tsconfig.prod.json is not found

[ajhool]

Is this a bug report?

Just a documentation error. I am going to submit a PR immediately so I'm not filling out the rest of the suggested issue template (happy to do so, if need be).

The link at the end of this section:

### From `<2.16.0` to `>=2.16.0`

Since `2.16.0`, the template uses different `tsconfig` files for both development and production mode. For the latter, unfortunately, the path resolver is not smart enough to fall back to the basic `tsconfig.json` in case the expected `tsconfig.prod.json` is not present, so you have to create this file manually like shown [here](https://github.com/wmonk/create-react-app-typescript/blob/master/packages/react-scripts/template/tsconfig.prod.json).

points to https://github.com/wmonk/create-react-app-typescript/blob/master/packages/react-scripts/template/tsconfig.prod.json which returns a 404.

I believe the desired file is located, here: https://github.com/wmonk/create-react-app-typescript/blob/master/template/tsconfig.prod.json