Add article listing directories modified by vcpkg

[AugP]

We should have an article that explains which directories vcpkg may choose to write to by default for each OS and clarify whether users can safely delete them to save disk space.

[vicroms]

Should we turn this entry in our FAQ into a full article?

https://learn.microsoft.com/en-us/vcpkg/about/faq#how-can-i-remove-temporary-files