Improve docs on saving IBM credentials

docs/intro.txt

@@ -81,7 +81,8 @@ 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://github.com/Qiskit/qiskit-ibm-provider>`_. 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.
+Method 1:
+---------
 
 ::
 
@@ -99,11 +100,20 @@ If you are a member of an IBM hub then you can add this information to ``set_ibm
 
     set_ibmq_config(ibmq_api_token=ibm_token, instance=f"{hub}/{group}/{project}")
 
+.. currentmodule:: pytket.extensions.qiskit.backends.config
+
+.. autosummary::
+    :nosignatures:
+
+    QiskitConfig
+    set_ibmq_config
+
+Method 2:
+---------
+
 Alternatively you can use the following qiskit commands to save your credentials
 locally without saving the token in pytket config:
 
-.. note:: If using pytket-qiskit 0.39.0 or older you will have to use the deprecated :py:meth:`IBMQ.save_account` instead of :py:meth:`IBMProvider.save_account` in the code below.
-
 ::
 
     from qiskit_ibm_provider import IBMProvider
@@ -122,19 +132,11 @@ To see which devices you can access you can use the ``available_devices`` method
     my_instance=f"{hub}/{group}/{project}"
     ibm_provider = IBMProvider(instance=my_instance)
     backend = IBMQBackend("ibmq_nairobi") # Initialise backend for an IBM device
+
     backendinfo_list = backend.available_devices(instance=my_instance, provider=ibm_provider) 
     print([backend.device_name for backend in backendinfo_list])
 
 
-.. currentmodule:: pytket.extensions.qiskit.backends.config
-
-.. autosummary::
-    :nosignatures:
-
-    QiskitConfig
-    set_ibmq_config
-
-
 Converting circuits between pytket and qiskit
 =============================================
 
@@ -192,7 +194,7 @@ Every :py:class:`Backend` in pytket has its own ``default_compilation_pass`` met
      - `RemoveRedundancies <https://tket.quantinuum.com/api-docs/passes.html#pytket.passes.RemoveRedundancies>`_ 
 
 * [1] If no value is specified then ``optimisation_level`` defaults to a value of 2.
-* [2] self.rebase_pass is a rebase to the gateset supported by the backend, For IBM quantum devices that is {X, SX, Rz, CX}.
+* [2] self.rebase_pass is a rebase to the gateset supported by the backend, For IBM quantum devices and emulators that is either {X, SX, Rz, CX} or {X, SX, Rz, ECR}. The more idealised Aer simulators have a much broader range of supported gates.
 * [3] Here :py:class:`CXMappingPass` maps program qubits to the architecture using a `NoiseAwarePlacement <https://tket.quantinuum.com/api-docs/placement.html#pytket.placement.NoiseAwarePlacement>`_