Update docs to reflect current usage of example (#1610)

modified:   candle-examples/examples/onnx/README.md

candle-examples/examples/onnx/README.md

@@ -1,10 +1,39 @@
 ## Using ONNX models in Candle
 
-This example demonstrates how to run ONNX based models in Candle, the model
-being used here is a small sequeezenet variant.
+This example demonstrates how to run [ONNX](https://github.com/onnx/onnx) based models in Candle.
 
-You can run the example with the following command:
+It contains small variants of two models, [SqueezeNet](https://arxiv.org/pdf/1602.07360.pdf) (default) and [EfficientNet](https://arxiv.org/pdf/1905.11946.pdf).
+
+You can run the examples with following commands:
 
 ```bash
-cargo run --example squeezenet-onnx --release -- --image candle-examples/examples/yolo-v8/assets/bike.jpg
+cargo run --example onnx --features=onnx --release -- --image candle-examples/examples/yolo-v8/assets/bike.jpg
+```
+
+Use the `--which` flag to specify explicitly which network to use, i.e.
+
+```bash
+$ cargo run --example onnx --features=onnx --release -- --which squeeze-net --image candle-examples/examples/yolo-v8/assets/bike.jpg
+
+    Finished release [optimized] target(s) in 0.21s
+     Running `target/release/examples/onnx --which squeeze-net --image candle-examples/examples/yolo-v8/assets/bike.jpg`
+loaded image Tensor[dims 3, 224, 224; f32]
+unicycle, monocycle                               : 83.23%
+ballplayer, baseball player                       : 3.68%
+bearskin, busby, shako                            : 1.54%
+military uniform                                  : 0.78%
+cowboy hat, ten-gallon hat                        : 0.76%
+```
+
+```bash
+$ cargo run --example onnx --features=onnx --release -- --which efficient-net --image candle-examples/examples/yolo-v8/assets/bike.jpg
+
+    Finished release [optimized] target(s) in 0.20s
+     Running `target/release/examples/onnx --which efficient-net --image candle-examples/examples/yolo-v8/assets/bike.jpg`
+loaded image Tensor[dims 224, 224, 3; f32]
+bicycle-built-for-two, tandem bicycle, tandem     : 99.16%
+mountain bike, all-terrain bike, off-roader       : 0.60%
+unicycle, monocycle                               : 0.17%
+crash helmet                                      : 0.02%
+alp                                               : 0.02%
 ```