docs: update contributing.md

Author: rickstaa

CONTRIBUTING.md

@@ -17,7 +17,7 @@ We use github to host code, track issues and feature requests, and accept pull r
 
 Pull requests are the best way to propose changes to the codebase (we use [Github Flow](https://docs.github.com/en/get-started/quickstart/github-flow)). We actively welcome your pull requests:
 
-1. Fork the repo and create your branch from `master`.
+1. Fork the repo and create your branch from `main`.
 2. Add tests if you've added code that should be tested.
 3. If you've changed APIs, update the documentation.
 4. Ensure the test suite passes.