docs: clarify user management

This is a change that was spawned by this conversation: https://discuss.openedx.org/t/how-to-run-cairn/12083

Apparently, it's not quite obvious that users can import the default
dashboard using the CLI.

README.rst

@@ -61,10 +61,16 @@ Then, restart your platform and run the initialization scripts::
 
     tutor local launch
 
-Open http(s)://data.<YOUR_LMS_HOST> in your browser. When running locally, this will be http://data.local.edly.io. (http://data.local.edly.io:2247 in development). Users authenticate with their LMS user. By default, they have access to the data generated by the courses in which they have the "staff role". To convert an existing user to administrator status, run::
+Open http(s)://data.<YOUR_LMS_HOST> in your browser. When running locally, this will be http://data.local.edly.io. (http://data.local.edly.io:2247 in development). Users authenticate with their LMS user. By default, they have access to the data generated by the courses in which they have the "staff role". Once a user has successfully logged-in, their account can be modified with the ``cairn-createuser`` command.
+
+For instance, to convert an existing user to administrator status, run::
 
     tutor local do cairn-createuser --admin YOURUSERNAME YOURUSERNAME@YOUREMAIL.COM
 
+To add the default dashboards to the new user, add the ``--bootstrap-dashboards`` option::
+
+    tutor local do cairn-createuser --bootstrap-dashboards YOURUSERNAME YOURUSERNAME@YOUREMAIL.COM
+
 Some event data might be missing from your dashboards: just start using your LMS and refresh your dashboard. The new events should appear immediately.
 
 .. image:: https://raw.githubusercontent.com/overhangio/tutor-cairn/master/screenshots/courseoverview-01.png
@@ -74,7 +80,12 @@ Some event data might be missing from your dashboards: just start using your LMS
 .. image:: https://raw.githubusercontent.com/overhangio/tutor-cairn/master/screenshots/courseoverview-03.png
     :alt: Course overview dashboard part 3
 
-⚠️ WARNING ⚠️ Previous versions of Cairn required manual user management. If you have an existing installation of Cairn, this behaviour will change when you upgrade to v16. To revert to the previous behaviour, see `"manual user management" <#manual-user-management>`__ below.
+By default, ``AUTH_ROLES_SYNC_AT_LOGIN`` is ``false`` which means admin can customize the permissions associated to a user. To disable this behaviour, modify the ``CAIRN_AUTH_ROLES_SYNC_AT_LOGIN`` setting::
+
+    tutor config save --set CAIRN_AUTH_ROLES_SYNC_AT_LOGIN=true
+    tutor local restart
+
+⚠️ WARNING ⚠️ Previous versions (v15 and earlier) of Cairn required manual user management. If you have an existing installation of Cairn, this behaviour will change when you upgrade to v16. To revert to the previous behaviour, see `"manual user management" <#manual-user-management>`__ below.
 
 
 Available metrics
@@ -110,27 +121,14 @@ By default, authentication uses single sign-on (SSO) with the LMS such that user
     tutor config save --set CAIRN_ENABLE_SSO=false
     tutor local restart
 
-SSO will then disabled, and only manually created users will be able to login. To create a user, run::
+SSO will then disabled, and only manually created users will be able to login. To create a user, run the ``cairn-createuser`` command, as explained above::
 
     tutor local do cairn-createuser --password=yourpassword YOURUSERNAME YOURUSERNAME@YOUREMAIL.COM
 
-To make this user an administrator, add the ``--admin`` option::
-
-    tutor local do cairn-createuser --admin YOURUSERNAME YOURUSERNAME@YOUREMAIL.COM
-
-To add the default dashboards to the new user, add the ``--bootstrap-dashboards`` option::
-
-    tutor local do cairn-createuser --bootstrap-dashboards YOURUSERNAME YOURUSERNAME@YOUREMAIL.COM
-
- To restrict a given user to one or more courses or organizations, select the course IDs and/or organization IDS to which the user should have access::
+To restrict a given user to one or more courses or organizations, select the course IDs and/or organization IDS to which the user should have access::
 
     tutor local do cairn-createuser --course-id='course-v1:edX+DemoX+Demo_Course' YOURUSERNAME YOURUSERNAME@YOUREMAIL.COM
 
-By default, AUTH_ROLES_SYNC_AT_LOGIN is False which means admin can customize the permissions associated to a user. To disable this behaviour, modify the ``CAIRN_AUTH_ROLES_SYNC_AT_LOGIN`` setting::
-
-    tutor config save --set CAIRN_AUTH_ROLES_SYNC_AT_LOGIN=true
-    tutor local restart
-
 Refreshing course block data
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~