Placeholder files for Windows 10 OneDrive are not documented

[sba923]

https://docs.microsoft.com/en-us/windows/desktop/w8cookbook/placeholder-files documents placeholder files for Windows 8.0 OneDrive (somewhat).

There is no equivalent for Windows 10 OneDrive placeholder files.

Notably, the use of attribute bits (ReparsePoint, SparseFile, Offline, Pinned, Unpinned...) and of reparse point tags (IO_REPARSE_TAG_CLOUD*) is not documented.

FWIW, I've collected this data while working on PowerShell issues https://github.com/PowerShell/PowerShell/issues/8315 / https://github.com/PowerShell/PowerShell/issues/9461 and PR https://github.com/PowerShell/PowerShell/pull/8745