diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 94eafd3b..34881b82 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,9 +1,13 @@
-# Contributing
+# Development environment setup
+
+With [Node.js](https://nodejs.dev) installed, [`git clone` the repository](https://docs.github.com/en/github/creating-cloning-and-archiving-repositories/cloning-a-repository-from-github/cloning-a-repository#cloning-a-repository) then run `npm install` and `npm run dev` to start the development server.
+
+# Merging user updates
 
 If you are a collaborator (with push permissions), you can merge any open PR with the following conditions:
 
 1. It passes the JSON validity test (this is a GitHub integration in Travis CI)
-2. Merge anything that adds or updates a `<user>.json` file
+2. It adds or updates a `<user>.json` file
 
 If you're unsure, cc @remy into the PR with a question and we can work out what to do.