updating docs with info for solo nbclassic install

Author: RRosio

docs/source/nbclassic.rst

@@ -65,11 +65,11 @@ Jupyter Ecosystem in this `team-compass issue`_.
 You can install NbClassic, Notebook 7 and JupyterLab, all three of
 which will be providing different user interfaces that will be available
 on the same server. When Notebook 7 is available, the NbClassic UI, will
-be served at the ``/nbclassic/tree`` base URL rather than the 
-base URL ``/tree`` used otherwise. If you are using Notebook 7 along 
+be served at the ``/nbclassic/tree`` base path rather than the 
+base path ``/tree`` used otherwise. If you are using Notebook 7 along 
 with NbClassic, you wil also have JupyterLab installed as it is a 
 dependency of Notebook 7, and these front ends will be available 
-through the following base URLs: JupyterLab at ``/lab``, Notebook 7 at 
+through the following base paths: JupyterLab at ``/lab``, Notebook 7 at 
 ``/tree``, and NbClassic at ``/nbclassic/tree``.
 
 **NbClassic and Notebook 6.5.x**
@@ -78,8 +78,8 @@ As NbClassic provides the static assets for Notebook 6.5.x, while
 having both installed should cause no issues, the user interface provided
 by these two packages will be the same. These UIs would be available in
 different servers. An NbClassic instance will be at a server with the 
-``/tree`` URL and opening a Notebook 6.5.x instance will open on a 
-different server with the ``/tree`` URL as well, presenting the same 
+``/tree`` path and opening a Notebook 6.5.x instance will open on a 
+different server with the ``/tree`` path as well, presenting the same 
 static assets. When starting an instance of JupyterLab you will be able 
 to access the classic view of Notebook with NbClassic served on the same 
 server at ``/tree``. 
@@ -107,6 +107,17 @@ When only JupyterLab 4.x is installed, then NbClassic has to be installed
 explictly. They will run on the same server, and are reachable via 
 ``/tree`` for NbClassic, and ``/lab`` for JupyterLab.
 
+**NbClassic Independently**
+
+When you choose to install only NbClassic via ``pip install nbclassic``, 
+the classic Notebook UI will be presented at the ``/tree`` path. As the 
+other frontends are not installed, attempting to access the other paths 
+will return errors. Note that NbClassic being a Jupyter Server extension, 
+indicated Jupyter Server will be available. This provides an additional 
+way to view the NbClassic frontend. You would be able to  manually 
+enable the extension when running an instance of Jupyter Server, 
+``> jupyter server --ServerApp.jpserver_extensions="nbclassic=True"``, 
+which will provide the NbClassic frontend at ``/tree`` path when visited.
 
 .. _team-compass issue: https://github.com/jupyter/notebook-team-compass/issues/5#issuecomment-1085254000