Documentation: hyperv: Add overview of guest VM hibernation

Add documentation on how hibernation works in a guest VM on Hyper-V.
Describe how VMBus devices and the VMBus itself are hibernated and
resumed, along with various limitations.

Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/20250113145645.1320942-1-mhklinux@outlook.com


Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250113145645.1320942-1-mhklinux@outlook.com>