Add a prominent section explaining that feature PRs require prior
discussion (GitHub issue, Discussions, or direct communication with
maintainer). This helps ensure alignment with project vision, avoids
wasted effort, enables collaborative design, and prevents duplicate work.
The section includes:
- Clear requirement statement with warning
- Explanation of why this is important
- Step-by-step guide on how to contribute features
- Clarification that this applies to features, not bug fixes
Also updated Before You Start, PR Requirements, and Questions sections
to reference and reinforce this requirement.
