docs should import nbclassic

Author: echarles

docs/autogen_config.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 
 import os
-from notebook.notebookapp import NotebookApp
+from nbclassic.notebookapp import NotebookApp
 
 header = """\
 .. _config:

docs/source/conf.py

@@ -357,4 +357,4 @@
 spelling_word_list_filename='spelling_wordlist.txt'
 
 # import before any doc is built, so _ is guaranteed to be injected
-import notebook.transutils
+import nbclassic.transutils