docs: update images and add 'classic session launcher' description

docs/user_settings/user_settings.rst

@@ -76,6 +76,30 @@ before the page is refreshed.
    WebUI is open sourced, anyone who willing to make the translation better
    can contribute: https://github.com/lablup/backend.ai-webui.
 
+Automatic Update Check
+^^^^^^^^^^^^^^^^^^^^^^
+
+A notification window pops up when a new version of the Web-UI is detected.
+It works only in an environment where Internet access is available.
+
+Auto logout
+^^^^^^^^^^^
+
+Log out automatically when all Backend.AI Web-UI pages are closed except for
+pages created to run apps in session (e.g. jupyter notebook, web terminal,
+etc.).
+
+My Keypair information
+^^^^^^^^^^^^^^^^^^^^^^
+
+Every user has at least one or more keypairs. you can see access and secret keypair by clicking 
+Config button below. Remember that main access keypair is only one.
+
+.. image:: my_keypair_information.png
+   :width: 700
+   :align: center
+   :alt: My Keypair Information
+
 .. _user-ssh-keypair-management:
 
 SSH Keypair Management
@@ -116,31 +140,13 @@ please enter the keys inside, and click ``SAVE`` button. Now you can access to b
    :width: 400
    :align: center
 
+Classic Session Launcher
+^^^^^^^^^^^^^^^^^^^^^^^^
 
-Automatic Update Check
-^^^^^^^^^^^^^^^^^^^^^^
-
-A notification window pops up when a new version of the Web-UI is detected.
-It works only in an environment where Internet access is available.
-
-Auto logout
-^^^^^^^^^^^
-
-Log out automatically when all Backend.AI Web-UI pages are closed except for
-pages created to run apps in session (e.g. jupyter notebook, web terminal,
-etc.).
-
-My Keypair information
-^^^^^^^^^^^^^^^^^^^^^^
-
-Every user has at least one or more keypairs. you can see access and secret keypair by clicking 
-Config button below. Remember that main access keypair is only one.
-
-.. image:: my_keypair_information.png
-   :width: 700
-   :align: center
-   :alt: My Keypair Information
-
+From Backend.AI version 24.09, Backend.AI offers an improved version of the session launcher (NEO) as default.
+If you want to use the classic session launcher, you can turn on this option. 
+For instructions on how to use the classic session launcher, please refer to the following 
+`link <https://webui.docs.backend.ai/en/23.09_a/sessions_all/sessions_all.html>`_.
 
 EDIT BOOTSTRAP SCRIPT
 ^^^^^^^^^^^^^^^^^^^^^^^