* guix/ui.scm (relevance): Allow the "field" procedure of a metric to
return a list, and handle that case appropriately. Update docstring.
(%package-metrics): Add a metric for package outputs.
* guix/scripts/package.scm (find-packages-by-description): Update
docstring.
* tests/guix-package.sh: Add a test case to verify that package outputs are
included in search results.
Co-authored-by: Tobias Geerinckx-Rice <me@tobias.gr>