Update README.md (#850)

deploy/triton-inference-server/README.md

@@ -11,6 +11,9 @@ There are no additional dependencies needed to run this deployment, except a wor
 See https://github.com/WongKinYiu/yolov7#export for more info.
 
 ```bash
+#install onnx-simplifier not listed in general yolov7 requirements.txt
+pip3 install onnx-simplifier 
+
 # Pytorch Yolov7 -> ONNX with grid, EfficientNMS plugin and dynamic batch size
 python export.py --weights ./yolov7.pt --grid --end2end --dynamic-batch --simplify --topk-all 100 --iou-thres 0.65 --conf-thres 0.35 --img-size 640 640
 # ONNX -> TensorRT with trtexec and docker