Update README.md

Author: SkalskiP

README.md

@@ -401,7 +401,7 @@ from rfdetr import RFDETRBase
 
 model = RFDETRBase()
 
-model.train(dataset_dir=<DATASET_PATH>, epochs=10, batch_size=4, grad_accum_steps=4, lr=1e-4, output_dir=<OUTPUT_PATH>, )
+model.train(dataset_dir=<DATASET_PATH>, epochs=10, batch_size=4, grad_accum_steps=4, lr=1e-4, output_dir=<OUTPUT_PATH>, resume=<CHECKPOINT_PATH>)
 ```
 
 ### Early stopping