Add Chinese version of ai-shifu-course-creator skill

[heshaofu2]

What

Adds the Chinese (skills-zh) page for the existing ai-shifu-course-creator community skill (English page was merged earlier). Content is a full translation of the current English page.

Notes

• Frontmatter uses the slug-only format (slug: ai-shifu-course-creator), matching all existing skills-zh pages and how src/pages/zh/skills/[slug].astro loads Chinese content.
• Verified locally with astro build (135 pages, dist/zh/skills/ai-shifu-course-creator generated). Note: verification was done against the last buildable base, because the root package.json on current main was overwritten by fd2c6fd ("Add coding-agent skill v0.1.0") and npm run build no longer exists there — you may want to restore it separately.

🤖 Generated with Claude Code