v0.4.0-alpha.4

What's Changed

• docs: update adoption action version by @ChaoYuZhang001 in #17
• Prepare a portable Provider site artifact by @ChaoYuZhang001 in #18
• Add the plugin-author onboarding path by @ChaoYuZhang001 in #19

Full Changelog: v0.4.0-alpha.3...v0.4.0-alpha.4