create-react-app with --typescript doesn't work when installed globally - update docs accordingly

Created by: methodbox

Is this a bug report?

No - documentation issue.

Did you try recovering your dependencies?

No. Not the issue.

Not relevant. (Write your answer here.)

Which terms did you search for in User Guide?

The user guide is incorrect, by your own statement here: https://github.com/facebook/create-react-app/issues/6319#issuecomment-459627529 - unfortunately, this wasn't ever corrected, and I believe the behavior is still actually broken, aside from the docs not being updated.

Not relevant. (Write your answer here if relevant.)

Environment

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Steps to Reproduce

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Expected Behavior

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Actual Behavior

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Reproducible Demo

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TL; DR:

This was closed: https://github.com/facebook/create-react-app/issues/6319

This was the answer given: https://github.com/facebook/create-react-app/issues/6319#issuecomment-459627529 - which works, but doesn't match what the docs say (despite the answer explicitly stating so).

This is still wrong: https://facebook.github.io/create-react-app/docs/adding-typescript

I'd be happy to submit a pull request to update the documentation to provide a warning about this, but as it stands you're likely to keep getting bug reports about it.

I've found at least 3 of them myself.