add running with modules to prep work

3_documenting_and_testing/prep_work.md

@@ -10,4 +10,7 @@ Familiarize yourself with these resources for understanding and discussing code
 
 - Read through [Behavior, Strategy, Implementation](./behavior_strategy_implementation.md)
 - Read through the [Code Review Checklist](./code_review_checklist.md)
-- Study and run the [`/examples`](./examples/)
+- Study and run the [`/examples`](./examples/).  Practice using these commands with `fibonacci_list.py` and `tests/test_fibonacci.py`:
+  - print the docstring: `$ python -m pydoc path/to/file.py`
+  - run the doctests: `$ python -m doctest -v path/to/file.py`
+  - run the tests using `$ python -m unittest path/to/tests/test_file.py`