Update FAQ.md for Anti-Virus/Malware Scanner Detections

[BChip]

Added in more context about the dontofferthroughwuau registry key and how some malware scanners or anti-virus might pick up on this as Potentially Unwanted Modification (PUM)

[hellzerg]

@BChip Nice finding. I consider removing the specific tweak in the next version. Thanks for noticing and explanation.

[hellzerg]

I did remove the tweak.