Update SmartScreen policy information

[ericlaw1979]

Improve the information by explaining what settings actually do, and point to Edge policies for Edge in SmartScreen because the Windows policies do not work properly on Windows 11 2022 and earlier.

Why

• Old documentation was incorrect due to product bugs (drift of which registry keys were used); this mismatch led to ICMs.

Changes

• Replaces reference to outdated Windows policies with reference to current (and backward compatible) Edge policies.

[learn-build-service-prod]

Learn Build status updates of commit a19405e:

✅ Validation status: passed

File	Status	Preview URL	Details
windows/security/operating-system-security/virus-and-threat-protection/microsoft-defender-smartscreen/available-settings.md	✅Succeeded

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