add notebook directory for notebooks

README.md

@@ -15,7 +15,9 @@ Project Organization
     │   ├── processed      <- The final, canonical data sets for modeling.
     │   └── raw            <- The original, immutable data dump.
     │
-    ├── models             <- Trained and serialized models, model predictions, or model summaries
+    ├── notebooks          <- notebooks of prototypes etc
+    │
+    ├── models             <- trained and serialized models, model predictions, or model summaries
     │
     ├── references         <- Data dictionaries, manuals, and all other explanatory materials.
     │