doc fixes for alternate URL prefix

docs/source/interactive/htmlnotebook.txt

@@ -364,13 +364,13 b' The notebook dashboard (i.e. the default landing page with an overview'
 of all your notebooks) typically lives at a URL path of
 "http://localhost:8888/". If you want to have it, and the rest of the
 notebook, live under a sub-directory,
-e.g. "http://localhost:8888/ipython/", you can do so with command-line
-options like these:
+e.g. "http://localhost:8888/ipython/", you can do so with
+configuration options like these (see above for instructions about
+modifying ``ipython_notebook_config.py``)::
 
-  $ ipython notebook --NotebookApp.webapp_settings="\
-         {'base_project_url':'/ipython/', \
-          'base_kernel_url':'/ipython/', \
-          'static_url_prefix':'/ipython/static/'}"
+    c.NotebookApp.base_project_url = '/ipython/'
+    c.NotebookApp.base_kernel_url = '/ipython/'
+    c.NotebookApp.webapp_settings = {'static_url_prefix':'/ipython/static/'}
 
 .. _notebook_format: