[Slice 8] CLAUDE.md entry point + README "Adding content" section

[wab]

Parent

#21

What to build

Ship the documentation entry point so a new Ocobo team member who clones the repo can discover the authoring flow without prior briefing.

Concretely:

• Create CLAUDE.md at the repo root — Claude Code conventions: points to the 7 skills, summarises the canonical workflow (Notion draft → /new-<type> <url> → /publish-content), lists the traps (typo exerpt, slugs are kebab-case identity, URLs Blob obligatoires, multi-language paradigm per type, cross-refs strict).
• Update README.md with a new "Adding content" section above the existing "Asset Management" section. Mentions the prereqs (pnpm install, MCP Notion setup pointing to docs/mcp-notion-setup.md), the commands, and links to docs/notion-templates/.

Acceptance criteria

• A first-time team member following README.md from a fresh clone can: install deps, set up MCP Notion (via docs/mcp-notion-setup.md), and run /new-blog-post <url> end-to-end up to PR creation.
• CLAUDE.md is concise (no duplication with CONTEXT.md or the ADR), points to the canonical files.
• The 5 traps from the PRD are explicitly mentioned in CLAUDE.md.

Blocked by

• [Slice 7] translate-content skill #28 (full surface stable, including translation)