Bug#939862: installation-guide-amd64: "Windows 8 fast boot" is now "Windows 10 fast startup"

[Lou Poppler <LouPoppler@cableone.net>]

Package: installation-guide-amd64
Severity: minor
Tags: d-i

Dear Maintainer,

Buster installation guide section 3.6.4. documents the dangers of the Windows 8
"fast boot" feature.  Most users now have Windows 10, where this feature is
renamed "fast startup".  I suggest this section (and its title) should mention
both Windows versions, and both feature names.

I suggest also adding additional text something like: "Sometimes the Windows
Update mechanism has been known to automatically re-enable this feature, after
it has been previously disabled by the user.  It is suggested to re-check this
setting periodically."