Add basic example of tsconfig.json on the README

[yordis]

I am confused of where should I put outDir in the configuration so will be great if you could add some basic setup that people could follow

P.S: this is my first time with Typescript so basically this would help beginners 🔰

[icopp]

For this case, you don't want an outDir at all. The actual build/compile is all handled by Webpack.

I'll see about adding more explanatory stuff, but it'll take updating things for the latest create-react-app/react-app-rewire first.