wiki enhancement

[eitsupi]

I can't send PR to the wiki, so I'll post it here.

One of the things that puzzled me, expecting the same behavior as RStudio, was the difference in relative paths when running the code on RMarkdown.
On RStudio, the path will be relative to the .Rmd file, but on VSCode, it will be relative to the root of the project.
I think these differences can generally be resolved by using the here package, so could this be mentioned in the wiki?