Clarify CRA => Typescript docs regarding tsconfig.json

Created by: seanc-dev

Hey guys, bit of a newbie here but I went down a difficult to figure out rabbit hole because the docs for setting up Typescript in CRA say a tsconfig.json file will be created for you. This is only true when the app is created as a typescript app and not when converting an existing project. If this could be clarified with an example of a default tsconfig.json file it would help those relatively new to programming (like me).

Cheers!