Update MXNetONNXExport.ipynb (#86)

Author: hanzhaogang

tutorials/MXNetONNXExport.ipynb

@@ -7,7 +7,7 @@
     "# Exporting MXNet models to ONNX\n",
     "\n",
     "In this tutorial, we will show how you can save MXNet models to ONNX format.\n",
-    "ONNX exporter it a part of [MXNet repository](https://github.com/apache/incubator-mxnet/tree/master/python/mxnet/contrib/onnx/mx2onnx).\n",
+    "ONNX exporter is a part of [MXNet repository](https://github.com/apache/incubator-mxnet/tree/master/python/mxnet/contrib/onnx/mx2onnx).\n",
     "\n",
     "Current MXNet-ONNX import and export operator support and coverage can be found [here](Operator support and coverage - https://cwiki.apache.org/confluence/display/MXNET/ONNX):\n"
    ]
@@ -26,6 +26,7 @@
     "```bash\n",
     "pip install mxnet --pre\n",
     "```\n",
+    "For windows, type python -m pip install mxnet --pre in your cmd.exe window, make sure you have installed python properly",
     "\n",
     "* Note: ONNX exporter will be released as a part of MXNet v1.3. "
    ]