[Docs] Fix pre-commit hook setup command

[bokub]

Description

In the provided example, pretty-quick is installed locally, not globally, which may cause the hook to fail:

❯ git commit
.husky/pre-commit: 4: pretty-quick: not found
husky - pre-commit hook exited with code 127 (error)

This problem can be fixed by running "npx pretty-quick --staged" instead of just "pretty-quick --staged"

Maybe @typicode can confirm?

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N.B I've made changes to documentation only, so everything below is not applicable

Checklist

• I’ve added tests to confirm my change works.
• (If changing the API or CLI) I’ve documented the changes I’ve made (in the docs/ directory).
• (If the change is user-facing) I’ve added my changes to changelog_unreleased/*/XXXX.md file following changelog_unreleased/TEMPLATE.md.
• I’ve read the contributing guidelines.

✨Try the playground for this PR✨

[thorn0]

Confirmed: https://typicode.github.io/husky/#/?id=locally-installed-binaries