Init onnx convertor design doc

Yibing Liu · Yibing Liu · commit f754a86d6a2a · 2018-03-21T03:44:03.000-07:00
diff --git a/doc/fluid/design/onnx/onnx_convertor.md b/doc/fluid/design/onnx/onnx_convertor.md
@@ -0,0 +1,15 @@
+### Backgroud
+
+(@kuke)
+
+### How it works
+(@kuke)
+
+### Project structure
+(@pkuyym)
+
+### Usage
+(@pkuyym
+
+### Supported models
+(@kuke)
