Get started on README changes

README.md

@@ -160,6 +160,21 @@ No data should be lost since it is just re-generateable build files.
 [pythondevmode]: https://docs.python.org/3/library/devmode.html
 [pudb]: https://pypi.org/project/pudb/
 
+## Setting up a development environment
+
+Now that you have installed all the dependencies and know how to run the tests,
+it's possible that you would like to make code changes and submit them for
+review.
+
+We use [pre-commit](https://pre-commit.com) to run some checks that ensure that
+our codebase is clean and consistent.
+
+Install it with `pip install pre-commit`, and install the pre-commit hooks with
+`pre-commit install`.
+
+The same linters run in CI, and you can also run them with `pre-commit run
+--all-files`.
+
 # "Where is my user data and config stored?"
 
 It depends: