Fix platyPS schema problems in reference/ folder

[vors]

This is a second part of #798

[saldana]

✅ Validation status: passed

File	Status	Preview URL	Details
reference/4.0/Microsoft.PowerShell.Utility/Get-Culture.md	✅Succeeded		Details
reference/5.0/Microsoft.PowerShell.Core/Register-ArgumentCompleter.md	✅Succeeded		Details
reference/5.0/Microsoft.PowerShell.Utility/ConvertFrom-String.md	✅Succeeded		Details
reference/5.0/Microsoft.PowerShell.Utility/Get-Culture.md	✅Succeeded		Details
reference/5.0/Microsoft.PowerShell.Utility/Get-Runspace.md	✅Succeeded		Details
reference/5.1/Microsoft.PowerShell.Core/Register-ArgumentCompleter.md	✅Succeeded		Details
reference/5.1/Microsoft.PowerShell.Utility/ConvertFrom-String.md	✅Succeeded		Details
reference/5.1/Microsoft.PowerShell.Utility/Get-Culture.md	✅Succeeded		Details

For more details, please refer to the build report.

Note: If you changed an existing file name or deleted a file, broken links in other files to the deleted or renamed file are listed only in the full build report.

[saldana]

✅ Validation status: passed

File	Status	Preview URL	Details
reference/4.0/Microsoft.PowerShell.Utility/Get-Culture.md	✅Succeeded		Details
reference/5.0/Microsoft.PowerShell.Core/Register-ArgumentCompleter.md	✅Succeeded		Details
reference/5.0/Microsoft.PowerShell.Utility/ConvertFrom-String.md	✅Succeeded		Details
reference/5.0/Microsoft.PowerShell.Utility/Get-Culture.md	✅Succeeded		Details
reference/5.0/Microsoft.PowerShell.Utility/Get-Runspace.md	✅Succeeded		Details
reference/5.1/Microsoft.PowerShell.Core/Register-ArgumentCompleter.md	✅Succeeded		Details
reference/5.1/Microsoft.PowerShell.Utility/ConvertFrom-String.md	✅Succeeded		Details
reference/5.1/Microsoft.PowerShell.Utility/Get-Culture.md	✅Succeeded		Details

For more details, please refer to the build report.

Note: If you changed an existing file name or deleted a file, broken links in other files to the deleted or renamed file are listed only in the full build report.

[juanpablojofre]

@vors !
Hi Sergei,
I'm not quite convinced of your edits to ConvertFrom-String reference topic.
Can you explain why you removed the samples written in PowerShell language and replaced with output only content?

[vors]

Hi @juanpablojofre

1. PlatyPS schema at the moment doesn't support more then 1 scriptblock in the example, so it has to be concatenated, if you want to produce maml.
2. It redundant because PS code is duplicated in the first snippet and then after C:\> in the second snippet. I.e.
   

Why do we need "Hello World" | ConvertFrom-String twice?

I should admit that even with my changes ConvertFrom-String.md still doesn't build, because of PowerShell/platyPS#239

If you'd like, I can separate changes to ConvertFrom-String.md into a separate PR and we can merge the rest of them. That way we can discuss this changes and not block other changes.

[vors]

I opened 2 separate PRs for these changes.