here:

https://quarto.org/docs/websites/website-navigation.html

target sets the target attribute of the link, allowing for things like new windows when clicking navbar or sidebar links.
cwickham
2023-05-25T19:35:22Z
dragonstyle
documentation triaged-to
v1.4
open
Add `target` to nav item options
https://github.com/quarto-dev/quarto-cli/issues/5688