docs: point to new option for better assurance on tag listing

cli/recipe/upgrade.go

@@ -157,7 +157,7 @@ You may invoke this command in "wizard" mode and be prompted for input:
 			sort.Sort(tagcmp.ByTagDesc(compatible))
 
 			if len(compatible) == 0 && !internal.AllTags {
-				logrus.Info(fmt.Sprintf("no new versions available for %s, %s is the latest", image, tag))
+				logrus.Info(fmt.Sprintf("no new versions available for %s, assuming %s is the latest (use -a/--all-tags to see all anyway)", image, tag))
 				continue // skip on to the next tag and don't update any compose files
 			}