Remove --single-quote from prettier examples

[brlewis]

Passing options directly to the cli is not great practice, since default editor integrations won't pick it up and many people are just going to copy paste this snippet. This change removes that customization and prettier will use its very sane defaults.

Closes#7615

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[brlewis]

There's no original creative work in this PR. Everything is copied verbatim from #7646 including the commit message. EDIT: I see from the CLA that I'm required to say "Submitted on behalf of a third-party: @heyimalex "

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[ianschmitz]

Thanks!