list supported types in usage/help message.

go/qst.go

	log.SetFlags(log.Ldate | log.Ltime | log.Lshortfile)
	flag.Usage = func() {
		fmt.Fprintf(os.Stderr, "Usage: %s <file>\n", os.Args[0])
		fmt.Fprintf(os.Stderr, "Usage: %s <file>\n\n", os.Args[0])
		flag.PrintDefaults()
		fmt.Fprintf(os.Stderr, "\nSupported project types: \n")
		for _, project := range detect.ProjectTypes {
			paddedId := fmt.Sprintf("%s%s", project.Id, strings.Repeat(" ", 30-len(project.Id)))
			fmt.Fprintf(os.Stderr, "\t%s- %v\n", paddedId, project.Commands[*phase])
		}
	}
	flag.Parse()