Add DEVELOP.md as guide for adding onnx models

Signed-off-by: Aivin V. Solatorio <avsolatorio@gmail.com>

DEVELOP.md

@@ -0,0 +1,35 @@
+# ONNX models generation
+
+The transformers.js library uses ONNX models. To convert a Hugging Face model to ONNX, you can use the `optimum-cli` tool. The following commands show how to convert a Hugging Face model to ONNX and quantize it using the `optimum-cli` tool.
+
+```bash
+MODEL_NAME=GIST-all-MiniLM-L6-v2
+
+poetry run optimum-cli export onnx -m avsolatorio/${MODEL_NAME} ${MODEL_NAME}_onnx/
+poetry run optimum-cli onnxruntime quantize \
+  --avx512 \
+  --onnx_model ${MODEL_NAME}_onnx -o ${MODEL_NAME}_onnx_quantized
+```
+
+We then upload this to the huggingface model repository. The onnx models must be in the `onnx/` folder in the repository.
+
+```bash
+git clone https://huggingface.co/avsolatorio/${MODEL_NAME}
+cd ${MODEL_NAME}
+
+if [ ! -d "onnx" ]; then
+    mkdir onnx && cd onnx
+
+    # Copy the onnx model
+    rsync -avP ../../${MODEL_NAME}_onnx/model.onnx onnx/
+
+    # Copy the quantized onnx model
+    rsync -avP ../../${MODEL_NAME}_onnx_quantized/model_quantized.onnx onnx/
+    rsync -avP ../../${MODEL_NAME}_onnx_quantized/ort_config.json onnx/
+
+    # Commit and push
+    git add onnx
+    git commit -m "Add onnx models"
+    git push origin main
+fi
+```