Update docs with admin password

docs/contributing/dev-setup.rst

@@ -43,6 +43,14 @@ The easiest & safest way to develop & test TLJH is with `Docker <https://www.doc
 
       python3 /srv/src/bootstrap/bootstrap.py --admin admin
 
+  Or, if you would like to setup the admin's password during install,
+  you can use this command (replace "admin" with the desired admin username
+  and "password" with the desired admin password):
+
+   .. code-block:: console
+
+      python3 /srv/src/bootstrap/bootstrap.py --admin admin:password
+
    The primary hub environment will also be in your PATH already for convenience.
 
 #. You should be able to access the JupyterHub from your browser now at

docs/howto/admin/admin-users.rst

@@ -19,7 +19,8 @@ so attackers can not easily gain control of the system.
 .. important::
 
    You should make sure an admin user is present when you **install** TLJH
-   the very first time. The ``:ref:`--admin <topic/customizing-installer/admin>```
+   the very first time. It is recommended that you also set a password
+   for the admin at this step. The :ref:`--admin <topic/customizing-installer/admin>`
    flag passed to the installer does this. If you had forgotten to do so, the
    easiest way to fix this is to run the installer again.
 

docs/topic/customizing-installer.rst

@@ -20,18 +20,39 @@ This page documents the various options you can pass as commandline parameters t
 Adding admin users
 ===================
 
-``--admin <username>`` adds user ``<username>`` to JupyterHub as an admin user.
-This can be repeated multiple times.
+``--admin <username>:<password>`` adds user ``<username>`` to JupyterHub as an admin user
+and sets its password to be ``<password>``.
+Although it is not recommended, it is possible to only set the admin username at this point
+and set the admin password after the installation.
 
-For example, to add ``admin-user1`` and ``admin-user2`` as admins when installing, you
-would do:
+Also, the ``--admin`` flag can be repeated multiple times. For example, to add ``admin-user1``
+and ``admin-user2`` as admins when installing, depending if you would like to set their passwords
+during install you would:
+
+* set ``admin-user1`` with password ``password-user1`` and ``admin-user2`` with ``password-user2`` using:
+
+.. code-block:: bash
+
+    curl https://raw.githubusercontent.com/jupyterhub/the-littlest-jupyterhub/master/bootstrap/bootstrap.py \
+     | sudo python3 - \
+       --admin admin-user1:password-user1 --admin admin-user2:password-user2
+
+* set ``admin-user1`` and ``admin-user2`` to be admins, without any passwords at this stage, using:
 
 .. code-block:: bash
 
     curl https://raw.githubusercontent.com/jupyterhub/the-littlest-jupyterhub/master/bootstrap/bootstrap.py \
      | sudo python3 - \
        --admin admin-user1 --admin admin-user2
 
+* set ``admin-user1`` with password ``password-user1`` and ``admin-user2`` with no password at this stage using:
+
+.. code-block:: bash
+
+    curl https://raw.githubusercontent.com/jupyterhub/the-littlest-jupyterhub/master/bootstrap/bootstrap.py \
+     | sudo python3 - \
+       --admin admin-user1:password-user1 --admin admin-user2
+
 Installing python packages in the user environment
 ==================================================