Sandy Bridge HD 3000 ReservedMemory "patch" is useless

**UPDATE:** Unfortunately, this still does not work. See below.

As a follow up to this [issue](https://github.com/acidanthera/bugtracker/issues/2315).

The "HD3000: IGPU memory corruption errata" in OpenCore config.plist does not, in fact, do anything. Specifically, we are talking about this quirk under `UEFI\ReservedMemory`:

```xml

Address
268435456
Comment
HD3000: IGPU memory corruption errata
Enabled

Size
268435456
Type
Reserved

```

The [linked](https://github.com/acidanthera/bugtracker/issues/2315) acidanthera bug tracker issue explains the actual solution to HD 3000 graphical issues in detail.

This is a separate issue with the Dortania guide where the wording for [Sandy Bridge part](https://dortania.github.io/OpenCore-Install-Guide/config-laptop.plist/sandy-bridge.html) of the guide in the [ReservedMemory section](https://dortania.github.io/OpenCore-Install-Guide/config-laptop.plist/sandy-bridge.html#reservedmemory) has to be corrected:

"Used for exempting certain memory regions from OSes to use, mainly relevant for Sandy Bridge iGPUs or systems with faulty memory. Use of this quirk is not covered in this guide"

Suggested paragraph:

"Used for exempting certain (bad) memory regions from being used by the OS, mainly relevant for systems with faulty memory. Use of this quirk is not covered in this guide."

This also closes #234.