add training script

README.md

@@ -53,6 +53,8 @@ The model was trained using a subset of the [Smithsonian Butterfly Dataset 🤗]
 The training data was preprocessed to ensure consistent resolution and remove any identifying information or copyrighted images.
 The total size of the training dataset was approximately X images.
 
+[Training Script](./ddpm_butterflies_64.ipynb)
+
 ## Usage Examples:
 Example Python code snippets and instructions for using the model to generate butterfly images.
 ```