Improve README short cut
@@ -163,7 +163,7 @@ python PPOCRLabel.py
| Ctrl + R | Re-recognize the selected box |
| Ctrl + C | Copy and paste the selected box |
| Ctrl + Left Mouse Button | Multi select the label box |
-| Ctrl + X | Delete the selected box |
+| Alt + X | Delete the selected box |
| Ctrl + V | Check image |
| Ctrl + Shift + d | Delete image |
| D | Next image |
