update the README file to introduce the converter wizard CLI

tfjs-converter/README.md

@@ -54,6 +54,35 @@ __1. Install the TensorFlow.js pip package:__
 
 __2. Run the converter script provided by the pip package:__
 
+There are two way to trigger the model conversion:
+
+- The conversion wizard: `tensorflowjs_wizard`
+- Regular conversion script: `tensorflowjs_converter`
+
+To start the conversion wizard:
+```bash
+tensorflowjs_wizard
+```
+
+This tool will walk you through the conversion process and provide you with
+details explanations for each choice you need to make. Behind the scene it calls
+the converter script (`tensorflowjs_converter`) in pip package. This is the
+recommended way to convert a single model.
+
+There is also a dry run mode for the wizard, which will not perform the actual
+conversion but only generate the command for `tensorflowjs_converter` command.
+This generated command can be used in your own shell script.
+
+Here is an screen capture of the wizard in action. ![wizard](./tensorflowjs_wizard.gif)
+```bash
+tensorflowjs_wizard --dryrun
+```
+
+To convert a batch of models or integrate the conversion process into your own
+script, you should use the tensorflowjs_converter script.
+
+## Conversion flags
+
 The converter expects a __TensorFlow SavedModel__, __TensorFlow Hub module__,
 __TensorFlow.js JSON__ format, __Keras HDF5 model__, or __tf.keras SavedModel__
 for input.