docs: fix stale README claims
- "a claude code plugin" -> Claude Code AND Codex (codex install added in 38cf526)
- pub-search URL: pub-search.waow.tech -> the actual .mcp.json endpoint
(pub-search-by-zzstoatzz.fastmcp.app/mcp)
- local dev: `claude --plugin-dir .` (was ./protopack, a nonexistent subdir)
- note the vit auto-publish workflow
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>