Add explanation to run gtest (#3933)
Add explanation to run gtest (#3933)

Signed-off-by: Joe <16a9a54ddf4259952e3c118c763138e83693d7fd@preferred.jp>

Co-authored-by: Ashwini Khade <c033833d70de1f14d546d5b23d66cc02095a83ed@microsoft.com>
onnx/onnx,onnx/onnx,onnx/onnx,onnx/onnx