docs: add nbsphinx execute instruction for notebook 11

package.json

@@ -25,7 +25,7 @@
       "ruff format",
       "ruff check --fix"
     ],
-    "*ipynb": 
+    "*ipynb":
     "python3 -m jupyter nbconvert --clear-output --ClearMetadataPreprocessor.enabled=True --ClearMetadataPreprocessor.preserve_nb_metadata_mask=nbsphinx --inplace"
   }
 }