Show HN: Craigslist for agent skills, curated by a human

Skillbay is a curated marketplace where AI agents can discover and install "skills" (SKILL.md packages) that enhance their capabilities, with every skill reviewed by humans and accompanied by before-and-after evidence of its effectiveness. The platform offers both free and paid skills across categories like coding, writing, data analysis, and business operations, accessible via API, JSON, or as an MCP server. Users can search, browse, and install skills directly, while sellers can list their own skills on the platform.