Improved `export.py` usage examples (#6495)

* Improved `export.py` usage examples

* Cleanup

export.py

@@ -469,10 +469,10 @@ def run(data=ROOT / 'data/coco128.yaml',  # 'dataset.yaml path'
     f = [str(x) for x in f if x]  # filter out '' and None
     LOGGER.info(f'\nExport complete ({time.time() - t:.2f}s)'
                 f"\nResults saved to {colorstr('bold', file.parent.resolve())}"
-                f"\nVisualize with https://netron.app"
-                f"\nDetect with `python detect.py --weights {f[-1]}`"
-                f" or `model = torch.hub.load('ultralytics/yolov5', 'custom', '{f[-1]}')"
-                f"\nValidate with `python val.py --weights {f[-1]}`")
+                f"\nDetect:          python detect.py --weights {f[-1]}"
+                f"\nPyTorch Hub:     model = torch.hub.load('ultralytics/yolov5', 'custom', '{f[-1]}')"
+                f"\nValidate:        python val.py --weights {f[-1]}"
+                f"\nVisualize:       https://netron.app")
     return f  # return list of exported files/dirs