add week command

main.go

@@ -9,7 +9,8 @@ func commandsUsage() string {
 	return fmt.Sprintf(
 		`commands:
   path        %v
-`, commandPathDescription)
+  week        %v
+`, commandPathDescription, commandWeekDescription)
 }
 
 func main() {
@@ -17,6 +18,8 @@ func main() {
 		switch os.Args[1] {
 		case "path":
 			commandPath(os.Args[1:])
+		case "week":
+			commandWeek(os.Args[1:])
 		default:
 			fmt.Printf("unknow command `%v`\n\n", os.Args[1])
 			fmt.Printf("%v", commandsUsage())