(GH-8759) Update WideControl in about_Format.ps1xml

[michaeltlombardi]

PR Summary

Prior to this commit, the section in about_Format.ps1xml incorrectly
explained the <WideEntry> tag and did not mention the <WideItem> tag
at all.

This commit updates the section for clarity and documents the
<WideItem> tag and its valid child tags.

• Fixes about_Format.ps1xml WideControl tag section is missing <WideItem> tag. #8759

PR Context

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• Files in docs-conceptual

Cmdlet reference & about_ topics
When changing cmdlet reference or about_ topics, the changes should be copied to all
relevant versions. Check the boxes below to indicate the versions affected by this change.

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• Version 7.2 content
• Version 7.1 content
• Version 7.0 content
• Version 5.1 content

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[opbld33]

Docs Build status updates of commit 0d57a0e:

✅ Validation status: passed

File	Status	Preview URL	Details
reference/5.1/Microsoft.PowerShell.Core/About/about_Format.ps1xml.md	✅Succeeded	View (powershell-5.1)
reference/7.0/Microsoft.PowerShell.Core/About/about_Format.ps1xml.md	✅Succeeded	View (powershell-7)
reference/7.1/Microsoft.PowerShell.Core/About/about_Format.ps1xml.md	✅Succeeded	View (powershell-7.1)
reference/7.2/Microsoft.PowerShell.Core/About/about_Format.ps1xml.md	✅Succeeded	View (powershell-7.2)
reference/7.3/Microsoft.PowerShell.Core/About/about_Format.ps1xml.md	✅Succeeded	View (powershell-7.3)

For more details, please refer to the build report.

Note: Broken links written as relative paths are included in the above build report. For broken links written as absolute paths or external URLs, see the broken link report.

For any questions, please:

• Try searching the docs.microsoft.com contributor guides
• Post your question in the Docs support channel

[opbld32]

Docs Build status updates of commit ca967ef:

✅ Validation status: passed

File	Status	Preview URL	Details
reference/5.1/Microsoft.PowerShell.Core/About/about_Format.ps1xml.md	✅Succeeded	View (powershell-5.1)
reference/7.0/Microsoft.PowerShell.Core/About/about_Format.ps1xml.md	✅Succeeded	View (powershell-7)
reference/7.1/Microsoft.PowerShell.Core/About/about_Format.ps1xml.md	✅Succeeded	View (powershell-7.1)
reference/7.2/Microsoft.PowerShell.Core/About/about_Format.ps1xml.md	✅Succeeded	View (powershell-7.2)
reference/7.3/Microsoft.PowerShell.Core/About/about_Format.ps1xml.md	✅Succeeded	View (powershell-7.3)

For more details, please refer to the build report.

Note: Broken links written as relative paths are included in the above build report. For broken links written as absolute paths or external URLs, see the broken link report.

For any questions, please:

• Try searching the docs.microsoft.com contributor guides
• Post your question in the Docs support channel