tiny11Coremaker.ps1: $mainOSDrive vs. $ScratchDisk

[Giermann]

The script tiny11Coremaker.ps1 uses "$mainOSDrive" instead of "$ScratchDisk", as tiny11maker.ps1 does.
But in the OSCDIMG command, $ScratchDisk is being used, maybe caused by Copy&Paste.
This leads to:
ERROR: Could not open boot sector file "\tiny11\boot\etfsboot.com"

Instead of simply fixing the variable name, it would be helpful to fully copy the setting of "$ScratchDisk" from tiny11maker.ps1 to have it configurable during image creation...