Enable arrow-key navigation (#2153)

Co-authored-by: Svetlana Karslioglu <svekars@fb.com>

Author: mthrok

conf.py

@@ -204,6 +204,7 @@
     'pytorch_project': 'tutorials',
     'collapse_navigation': False,
     'display_version': True,
+    'navigation_with_keys': True,
     'logo_only': False,
     'analytics_id': 'UA-117752657-2',
 }