Add standard docs in the repo

[iSazonov]

We need to add standard documents in the repo like Description, Contribution docs, CoC, Maintainers and so on.

In Contribution docs we should have module naming conventions:
from @SteveL-MSFT :

When we publish to PSGallery, we require the Microsoft namespace. @iSazonov, can you open a new issue to indicate this requirement in the Contribution docs for new modules? We are sticking with the Microsoft.PowerShell.* format for naming as other Microsoft teams may use Microsoft.* to avoid conflicts.