Write a developer onboarding guide

Help me write a developer onboarding guide.
Inputs: repo; audience.

1. Document a clean-environment path to first success.
2. explain key modules and change entry points.
3. include expected checks, troubleshooting and ownership.

Deliver: Guide, Verification log, Open questions.
Clarify critical gaps, separate facts from assumptions, and do not invent data, citations or completed actions.

My material: [fill in here]

Before you start

Provide repo; audience.