Extend show_help with packages-with-index (#160)

- add missing option description in usage message

Ref: 3e08cca

Signed-off-by: Michal Biesek <michalbiesek@gmail.com>

cr.sh

@@ -35,6 +35,7 @@ Usage: $(basename "$0") <options>
     -s, --skip-packaging          Skip the packaging step (run your own packaging before using the releaser)
         --skip-existing           Skip package upload if release exists
     -l, --mark-as-latest          Mark the created GitHub release as 'latest' (default: true)
+        --packages-with-index     Upload chart packages directly into publishing branch
 EOF
 }