docs/content/reference: fix typo in /reference/file-formats.md

[VinozzZ]

What does this change

This PR fix some typos in the file fomrats documentation

What issue does it fix

N/A

Notes for the reviewer

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• Did you write tests?
• Did you write documentation?
• Did you change porter.yaml or a storage document record? Update the corresponding schema file.
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• Comment with /azp run test-porter-release if a magefile or build script was modified
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[carolynvs]

Oops! Now the whole world knows that a) I copy/paste and b) I don't bother reading what I copy/paste. 🤦‍♀️

Thanks for the fix!