docs : update README.md for whisper.objc app (#2569)

examples/whisper.objc/README.md

@@ -26,10 +26,17 @@ If you don't want to convert a Core ML model, you can skip this step by creating
 mkdir models/ggml-base.en-encoder.mlmodelc
 ```
 
-## Core ML
-
-Follow the [`Core ML support` section of readme](../../README.md#core-ml-support) to convert the model.
-That is all the needs to be done to use the Core ML model in the app. The converted model is a
-resource in the project and will be used if it is available. Note that the Core ML model is only
-used for the encoder, the decoder which is in the ggml model is still required so both need to
-be available.
+### Core ML support
+1. Follow all the steps in the `Usage` section, including adding the ggml model file.  
+The ggml model file is required as the Core ML model is only used for the encoder. The
+decoder which is in the ggml model is still required.
+2. Follow the [`Core ML support` section of readme](../../README.md#core-ml-support) to convert the
+model.
+3. Add the Core ML model (`models/ggml-base.en-encoder.mlmodelc/`) to `whisper.swiftui.demo/Resources/models` **via Xcode**.
+
+When the example starts running you should now see that it is using the Core ML model:
+```console
+whisper_init_state: loading Core ML model from '/Library/Developer/CoreSimulator/Devices/25E8C27D-0253-4281-AF17-C3F2A4D1D8F4/data/Containers/Bundle/Application/3ADA7D59-7B9C-43B4-A7E1-A87183FC546A/whisper.swiftui.app/models/ggml-base.en-encoder.mlmodelc'
+whisper_init_state: first run on a device may take a while ...
+whisper_init_state: Core ML model loaded
+```