[PATCH] doc: update instructions for Windows builds

[Thomas Monjalon]

12/11/2025 03:41, Andre Muezerie:
> Updated some external links and removed a note which does not
> apply to MSVC builds anymore.
> 
> Also reworded a sentence clarifying how to open a Visual Studio
> Developer Command Prompt from CMD and Powershell, as the
> original text could induce people to run VsDevCmd.bat from
> a Powershell prompt, which does not work.
> 
> Signed-off-by: Andre Muezerie <andremue at linux.microsoft.com>

Applied, thanks.