cmd help message

Author: Oaklight

README.md

@@ -1,2 +1,12 @@
 # kvm-cold-backup
 kvm cold backup shell script, naive but always works.
+
+```bash
+$ ./virt-backup 
+Usage: ./virt-backup [options]
+Options:
+  -b, --backup <domain> <backup_path>    Backup and package the KVM virtual machine.
+  -r, --restore <backup_file_path>       Restore the KVM virtual machine from a backup file.
+  -h, --help                             Show this help message.
+```
+