Need to document that Out-GridView is only available on Windows

[rjmholt]

The Out-GridView document does not mention that it's only available on Windows.

It should do that, and ideally mention Microsoft.PowerShell.GraphicalTools as the cross-platform option.

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Document Details

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• ID: e2442949-6488-2ef1-f5d3-fa99b97658cd
• Version Independent ID: 217c0b18-24d5-6e58-506b-0cd849fa956c
• Content: Out-GridView (Microsoft.PowerShell.Utility)
• Content Source: reference/7.0/Microsoft.PowerShell.Utility/Out-GridView.md
• Product: powershell
• GitHub Login: @JamesWTruher
• Microsoft Alias: jimtru

[sdwheeler]

Actually the doc does say that it is Windows only but I can add a link to the GraphicalTools module.