update credentials docs

docs/intro.txt

@@ -65,8 +65,6 @@ In this section we are assuming that you have set the following variables with t
     group = '<your_group_here>'
     project = '<your_project_here>'
 
-.. note:: The documentation below is correct as of pytket-qiskit version 0.40.0 and newer. In the 0.40.0 release pytket-qiskit moved to using the `qiskit-ibm-provider <https://qiskit.org/ecosystem/ibm-provider/tutorials/Migration_Guide_from_qiskit-ibmq-provider.html>`_. In pytket-qiskit versions 0.39.0 and older the parameters ``hub``, ``group`` and ``project`` were handled separately instead of a single ``instance`` string as in 0.40.0 and newer.
-
 ::
 
     from pytket.extensions.qiskit import set_ibmq_config
@@ -109,6 +107,8 @@ To see which devices you can access you can use the ``available_devices`` method
     backendinfo_list = backend.available_devices(instance=my_instance, provider=ibm_provider) 
     print([backend.device_name for backend in backendinfo_list])
 
+.. note:: The credentials documentation above is correct as of pytket-qiskit version 0.40.0 and newer. In pytket-qiskit versions 0.39.0 and older the parameters ``hub``, ``group`` and ``project`` were handled as separate kwargs instead of a single ``instance`` string as in 0.40.0 and newer. If you are using pytket-qiskit version 0.39 or older it is recommended to upgrade. See the IBM provider `migration guide <https://qiskit.org/ecosystem/ibm-provider/tutorials/Migration_Guide_from_qiskit-ibmq-provider.html>`_ for more information.
+
 
 Backends Available Through pytket-qiskit
 ========================================