Add SEO optimization

- Add meta tags (keywords, author, robots, canonical)
- Add Open Graph tags for social sharing
- Add Twitter card meta tags
- Add hreflang tags for EN/FR language alternates
- Add Schema.org structured data (JSON-LD)
- Create sitemap.xml
- Create robots.txt
- Add workflow documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

robots.txt

@@ -0,0 +1,6 @@
+# Atomaste robots.txt
+User-agent: *
+Allow: /
+
+# Sitemap location
+Sitemap: https://atomaste.com/sitemap.xml