Update README.md

Author: jpn--

README.md

@@ -5,3 +5,10 @@ This example demonstrates the SANDAG ABM3 model.  This is ActivitySim's
 
 A full-scale exercise of the model is available via the `exercise.py` script,
 which will download (large) data files to run the full-scale tests.
+
+You can also run a smaller sized example set using the data files included
+in this repository, using this command:
+
+```
+activitysim run -c configs/common -c configs/resident -d data -o output -s settings_mp.yaml --ext extensions
+```