Latest with many suggestions from Nate

docs/source/examples/cdr_qrack.md

@@ -15,7 +15,6 @@ kernelspec:
 
 In this tutorial, [Clifford Data Regression](../guide/cdr.md) (CDR) is used with [Qrack](https://qrack.readthedocs.io/en/latest/) and a Qiskit fake backend. 
 
-While the Users Guide and the [Cirq: 1D Ising Simultation](./quantum_simulation_1d_ising.md) use density matrices, this example uses estimation values.
 
 +++
 
@@ -140,9 +139,8 @@ def cirq_simulate(circuit: cirq.Circuit) -> np.ndarray:
 
 ## Executing CDR
 
-With the different executor functions defined for running the Qrack, Qiskit, and Cirq simulators, the mitiq `execute_with_cdr` function can be called.
+With the different executor functions defined for running the Qrack, Qiskit, and Cirq simulators, the `mitiq.cdr.execute_with_cdr` function can now be called.
 
-Before getting the results from using CDR, `cirq_simulate` is called to get the ideal expectation value from the circuit. Next, the circuit is run on the fake Qiskit backend, using `qiskit_noisy` in order to obtain an unmitigated expectation value for `00`. Finally, `execute_with_cdr` is called to obtain the mitigated expectation value.
 
 +++
 
@@ -160,7 +158,6 @@ print(f"Unmitigated expectation value from Qiskit Fake backend: {unmitigated_exp
 mitigated_expval = cdr.execute_with_cdr(
     circuit,
     qiskit_noisy,
-    observable=None,
     simulator=qrack_simulate,
     seed=0,
 )