New cmdlet Get-PnPContainerType and minor updates to docs.

[reshmee011]

Before creating a pull request, make sure that you have read the contribution file located at

https://github.com/pnp/powerShell/blob/dev/CONTRIBUTING.md

Type

• [ ] New Feature

What is in this Pull Request ?

files for new cmdlet Get-PnPContainerType

• src\Commands\Admin\GetContainerType.cs
• documentation\Get-PnPContainerType.md

Minor documentation updates related to permissions required and typo fixes.

• documentation\Get-PnPContainer.md
• documentation\Get-PnPContainerTypeConfiguration.md
• documentation\New-PnPContainerType.md
• documentation\Remove-PnPContainerType.md