add type annotations for adaptive/notebook_integration.py

Author: basnijholt

adaptive/notebook_integration.py

@@ -76,7 +76,7 @@ def ensure_plotly():
         raise RuntimeError("plotly is not installed; plotting is disabled.")
 
 
-def in_ipynb():
+def in_ipynb() -> bool:
     try:
         # If we are running in IPython, then `get_ipython()` is always a global
         return get_ipython().__class__.__name__ == "ZMQInteractiveShell"