Poor documentation of what it means to use --typescript option

Created by: theconnectionist

I was excited to see the new --typescript option. Used it to create a project, but there was no evidence that typescript support was added. Then I discovered a documentation page suggesting I should rename .js to .tsx and restart the server. Did that, but got the following error. Not clear why this is happening if I already created a project with --typescript option. The whole point of using create-react-app (for a newbie react developer) is to get started without messing with any configuration, but adding typescript support doesn't look straightforward.

Appreciate any help with clear instructions on what --typescript actually does. If it isn't creating the scaffolding for typescript, should I follow instructions to add typescript support to an existing create-react-app?

`We detected TypeScript in your project (src/App.tsx) and created a tsconfig.json file for you.

It looks like you're trying to use TypeScript but do not have typescript installed. Please install typescript by running npm install typescript. If you are not trying to use TypeScript, please remove the tsconfig.json file from your package root (and any TypeScript files).`