To bring this a little back on topic, here are some relevant links:
- Julia’s Release Process
- Making a Julia Release, JuliaCon 2023
- Julia CI (that’s the “QA”)
CONTRIBUTING.md
The policies for reviewing PRs are just the normal workflows for GitHub-based development. I suppose those are more or less implicit. And yes, it is assumed that people contributing to Julia or the documentation of any package are familiar with GitHub. Maybe that’s a bit of a barrier, but I’m not really sure how I would improve on that.
Actual core contributors can probably give you more details about the development/release/QA process. Your desire to see these things explained is absolutely not unreasonable. But I would assure you that Julia has quite strenuous QA, even if not everything might be written down or might be immediately obvious to a newcomer.