refactor: deprecate the --rm and --rm-container flags

These flags are not commonly invoked by users, causing issues when cleaning up old containers. Rather than instruct users to use some random flag, just change the default to what is likely to be more common.

plugins/cron/functions.go

@@ -33,7 +33,7 @@ func (t templateCommand) CronCommand() string {
 		return t.AltCommand
 	}
 
-	return fmt.Sprintf("dokku --rm run --cron-id %s %s %s", t.ID, t.App, t.Command)
+	return fmt.Sprintf("dokku run --cron-id %s %s %s", t.ID, t.App, t.Command)
 }
 
 func fetchCronEntries(appName string) ([]templateCommand, error) {