Typo in doc - missing \

[seewoo5]

I re-opened #39818, I think it is much faster to do so instead of fixing conflicts.

📝 Checklist

• The title is concise and informative.
• The description explains in detail what this PR is about.
• I have linked a relevant issue or discussion.
• I have created tests covering the changes.
• I have updated the documentation and checked the documentation preview.

⌛ Dependencies

[dimpase]

you don't need to close the PR if you want to overwrite its branch : you can always git push -f

[github-actions]

Documentation preview for this PR (built with commit a06abcd; changes) is ready! 🎉
This preview will update shortly after each push to this PR.

[seewoo5]

you don't need to close the PR if you want to overwrite its branch : you can always git push -f

Thanks, I'd do it for other PRs if necessary.