Doc Out-Gridview, Show-Command and Get-Help -ShowWIndow for PS7

[SteveL-MSFT]

Out-GridView and Show-Command haven't changed (unless Show-Command doc mentions workflow which is not supported). Get-Help -ShowWindow was removed and added back and working now.

Context of the issue

• URL to the article (Docs or GitHub URL): Pending PR Add GraphicalHost assembly to enable Out-GridView, Show-Command, and Get-Help -ShowWindow PowerShell/PowerShell#10899

• Issue affects the following content (check all that apply):

  Cmdlet reference & about_ topics

  • Version 7 content
  • Version 6 content
  • Version 5.1 content

  Conceptual articles

  • Fundamental conceptual articles
  • Script sample articles
  • DSC articles
  • Gallery articles
  • JEA articles
  • WMF articles
  • SDK articles

• Is the issue specific to a platform (Y/N - Win/macOS/Linux):

Detailed description of the issue

[sdwheeler]

I need to add Show-Command to this PR.