Expand Lr91 README.md

Author: christopher-wild

examples/lr91/README.md

@@ -10,11 +10,15 @@ cause APD90 to increase, and increasing G_Na and G_Kp to have no significant eff
 can be found in Section 5.2 of the paper.
 
 ## How to run
+There are two versions of this case study:
+1. `causal_test_max_conductances.py` which has a for loop to iteratively call the `causal_test_engine`
+2. `causal_test_max_conductances_test_suite.py`, which uses the `causal_test_suite` object to interact with the `causal_test_engine`
+
 To run this case study:
 1. Ensure all project dependencies are installed by running `pip install .` in the top level directory
    (instructions are provided in the project README).
 2. Change directory to `causal_testing/examples/lr91`.
-3. Run the command `python causal_test_max_conductances.py`
+3. Run the command `python causal_test_max_conductances.py` or `python causal_test_max_conductances_test_suite.py`
 
 This should print a series of causal test results covering the effects of a range of different sized interventions made
 to the inputs on APD90, and should also plot Figure 2 from the paper.