Merge pull request #111 from NethServer/sdl-6994

Update migration.rst with ns7admin user creation and removal process NethServer/dev#6994

migration.rst

@@ -47,10 +47,11 @@ The migration procedure will add NS7 as special node of the NethServer 8 cluster
    - ``NS8 leader node``: the host name or IP address of NethServer 8 cluster leader node
 
    - ``NS8 admin username`` and ``NS8 admin password``: administrator
-     credentials for the leader node. As a best practice, create a
-     dedicated user from the :ref:`administrators-section` page and delete
-     the user once the migration has been completed. Please note that the
-     user must have 2FA disabled.
+     credentials for the leader node. 
+     These credentials are solely used to create a ``ns7admin1`` admin account in NS8
+     (note that the trailing '1' may actually be any number),
+     reserved for the NS7 migration tool. Ensure that this account is automatically
+     removed at the end of the migration.
 
    - uncheck the ``TLS validation`` option if the leader node does not have a valid TLS certificate