Update to installer for Windows

Quark 20.04 Focal installer for Windows has been updated and it brings a few important bug and security fixes. The new Windows installer is now available for download from the stable section https://sourceforge.net/projects/quark-os/files/stable/installer-for-windows/
See the setup guide https://www.q4os.org/dqa014.html for Q4OS, which is applicable to Quark as well.