feat: add automated PR quality checks and PR link extraction scripts

- Introduce `.github/scripts/check-quality.js` to automate validation of PRs against minimum standards from `CONTRIBUTING.md`:
  - Checks repo accessibility, go.mod presence, SemVer release, Go Report Card grade, pkg.go.dev, and coverage link.
  - Outputs a markdown report and sets fail status for critical issues.
- Add `.github/scripts/extract-pr-links.js` to extract required links from PR body and format a review comment.
- Update workflow to run these scripts and post results as PR comments.
- Update `CONTRIBUTING.md` to clarify requirements and reference new automation.

fixed https://app.codacy.com/gh/avelino/awesome-go/pull-requests/5810/issues

Signed-off-by: Avelino <[email protected]>

Signed-off-by: Avelino <[email protected]>