[3.13] GH-87358: Add clarification about nargs and default argparse behaviour (GH-124094) (#124440)

GH-87358: Add clarification about nargs and default argparse behaviour (GH-124094)
(cherry picked from commit 20ccda000b5f8365d5f864fd07876804157c2378)

Co-authored-by: Savannah Ostrowski <savannahostrowski@gmail.com>
1 file changed