Add Development and contributing page Environment setup (wp-env with Docker, the dev and tests sites, overriding ports), the three test suites (PHPUnit integration single- and multi-site, Behat, PHPCS/lint), the plugin architecture (taxonomy, guest-author CPT, fallback model, key classes, block editor integration since 4.0), the PR workflow (target develop, CI bars, test expectations), the co-author/coauthor terminology rule from CONTRIBUTING.md, and the release process.

GaryJones committed Apr 24, 2026