Add claude-seo, claude-blog, claude-ads to Marketing & Content section

[AgriciDaniel]

Requesting addition of 3 established Claude Code skills. These could go under a new Marketing & Content section or under existing categories.

Suggested entries:

- [claude-seo](https://github.com/AgriciDaniel/claude-seo) — Comprehensive SEO suite with 30+ skills and 10 agents. Site audits, technical SEO, E-E-A-T, GEO, schema, local SEO. 4,567 stars.
- [claude-ads](https://github.com/AgriciDaniel/claude-ads) — Multi-platform paid advertising audit. Google/Meta/LinkedIn/TikTok/Microsoft Ads, 225+ checks, 18 skills. 2,217 stars.
- [claude-blog](https://github.com/AgriciDaniel/claude-blog) — Full-lifecycle blog engine. 17 commands, 12 templates, 100-point scoring, CMS integration. 455 stars.

All MIT licensed.