add password page in lobby, point to totp seed request when configured. closes https://github.com/opnsense/core/issues/4474

source/lobby.rst

@@ -18,4 +18,5 @@ and end your session. After initial installation, this is the first place you wi
 
    manual/gui
    manual/dashboard
+   manual/lobby_password
    manual/opnsense_tools

source/manual/lobby_password.rst

@@ -0,0 +1,13 @@
+====================================
+Password
+====================================
+
+The password page in the lobby offers the user the ability to change his or hers password and default settings.
+
+When The option :code:`User OTP seed` is enabled in the :menuselection:`System->Settings->Administration` page, one could also
+acquire a new OTP seed here.
+
+.. Warning::
+
+    Changing an OTP seed automatically invalidates the previous one, so only request a new one when you are able
+    to scan the new one using your mobile phone.