Update WinGet configuration file location & extension

[mdanish-kh]

The new convention for WinGet configuration files is to place them in a .config directory with file extension .winget. With .winget file extension, users can directly launch the configuration from file explorer by double-clicking. See https://learn.microsoft.com/en-us/windows/package-manager/configuration/create#file-naming-convention

[denelon]

I didn't see any references in https://github.com/microsoft/vscode/wiki/How-to-Contribute for using the WinGet Configuration file. I'm wondering if it makes sense to add an option for getting the prerequisites installed in docs somewhere.