The README section was gated on `readme: true` in the catalog YAML and no entry set it, so
all 222 plugin pages shipped without one. READMEs now render for every GitHub/GitLab entry
(fetched at the reviewed sha, subdir first then repo root, common casings and docs/README.md
as fallbacks); `readme: false` opts an entry out. Build proof: 222/222 READMEs rendered.