Fix Readme; change cron doc to 5 minutes (instead of 1)

README.md

@@ -107,7 +107,7 @@ #### CRON
 Add this line in your crontab by typing `crontab -e`:
 
 ```bash
-5 * * * * * cd /path-to-your-project && php artisan schedule:run >> /dev/null 2>&1
+*/5 * * * * * cd /path-to-your-project && php artisan schedule:run >> /dev/null 2>&1
 ```
 
 ## Usage