Fix misplaced bracket in New-ADUser.md docs

[brantmeierz]

PR Summary

Single character change to correct misplaced square bracket in the New-ADUser usage template.

PR Checklist

• Descriptive Title: This PR's title is a synopsis of the changes it proposes.
• Summary: This PR's summary describes the scope and intent of the change.
• Contributor's Guide: I have read the [contributors guide][contrib].
• Style: This PR adheres to the [style guide][style].

[learn-build-service-prod]

PoliCheck Scan Report

The following report lists PoliCheck issues in PR files. Before you merge the PR, you must fix all severity-1 issues. Other issues are also a high priority. The AI Review Details column lists suggestions for either removing or replacing the terms. If you find a false positive result, mention it in a PR comment and include this text: #policheck-false-positive. This feedback helps reduce false positives in future scans.

✅ No issues found

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[learn-build-service-prod]

Learn Build status updates of commit 09cee58:

✅ Validation status: passed

File	Status	Preview URL	Details
docset/winserver2025-ps/ActiveDirectory/New-ADUser.md	✅Succeeded	View (WindowsServer2025-ps)

For more details, please refer to the build report.