updating content from zexuan's user test

docs/howto/auth/firstuse.rst

@@ -0,0 +1,36 @@
+.. _howto/auth/firstuse:
+
+==================================================
+Let users choose a password when they first log in
+==================================================
+
+The **First Use Authenticator** lets users choose their own password.
+Upon their first log-in attempt, whatever password they use will be stored
+as their password for subsequent log in attempts. This is
+the default authenticator that ships with TLJH.
+
+Enabling the authenticator
+==========================
+
+.. note:: the FirstUseAuthenticator is enabled by default in TLJH.
+
+#. Enable the authenticator and reload config to apply the configuration:
+
+   sudo -E tljh-config set auth.type firstuseauthenticator.FirstUseAuthenticator
+   sudo -E tljh-config reload
+
+Users who are currently logged in will continue to be logged in. When they
+log out and try to log back in, they will be asked to provide a username and
+password.
+
+Allowing anyone to log in to your JupyterHub
+============================================
+
+By default, you need to manually create user accounts before they will be able
+to log in to your JupyterHub. If you wish to allow **any** user to access
+the JupyterHub, run the following command.
+
+.. code-block:: bash
+
+   tljh-config set auth.FirstUseAuthenticator.create_users true
+   tljh-config reload