Merge pull request #173 from dleen/dleen/docs

Update docs to remove install command

Author: echarles

docs/source/nbclassic_dev_faq.rst

@@ -83,5 +83,4 @@ pending to be merged into the `Jupyter-contrib/jupyter_nbextensions_configurator
     $ pip install jupyter_nbextensions_configurator
     $ jupyter nbextension install --sys-prefix --py jupyter_nbextensions_configurator --overwrite
     $ jupyter nbextension enable --sys-prefix --py jupyter_nbextensions_configurator
-    $ jupyter serverextension install --sys-prefix --py jupyter_nbextensions_configurator --overwrite
-    $ jupyter serverextension enable --sys-prefix --py jupyter_nbextensions_configurator
+    $ jupyter serverextension enable --sys-prefix --py jupyter_nbextensions_configurator