Add a sprints quickstart guide for contributors

[Tim Schilling]

At the PyCon US 2026 sprints, Natalia, Jacob and I were referring to the same resources, processes and workflows, but lacked a singular place to send people to. There appears to be a need for a page to exist in the contribution docs for contribution sprint events. When people have access to an existing Django contributor, there's less of a need to read the contribution guidelines in full and more of a push to get the person productive.

This new page should contain a concise set of information that the Django contributor can send people to so that when they explain in person, there's a written version for the new contributor to refer back to.

The topics we should cover are:

• Quick set up for installing dependencies
• Show how to run tests, build docs
• Explain ​vulture method
• Give quick tips on assessing issues (>20000, pick a component they recognize)
• Give script to resume work off of someone else's branch

[Tim Schilling]

​The proposed changes can be found here. It's a rough first draft. I feel like the topics covered are good and would argue to keep them. I'm happy to see the details updated.