Update Windows tools documentation

[dinhngtu]

• Add more description of what the drivers do
• Add details about unsupported Windows versions
• Add more explicit mentions about the XSA-468 mitigation script usage

Before submitting the pull request, you must agree with the following statements by checking both boxes with a 'x'.

• "I accept that my contribution is placed under the CC BY-SA 2.0 license [1]."
• "My contribution complies with the Developer Certificate of Origin [2]."

[1] https://creativecommons.org/licenses/by-sa/2.0/
[2] https://docs.xcp-ng.org/project/contributing/#developer-certificate-of-origin-dco

[stormi]

Looks good overall. One change suggestion.

[dinhngtu]

Removed the part about the mitigation script not surviving reboots (because it does).