remark-lint-no-undefined-references

remark-lint rule to warn when Markdown references to undefined definitions are found. Current stable version: 5.0.2. Released as part of the remark-lint monorepo; patch updates follow release cadence of the monorepo. Differentiator: catches broken links in Markdown documents by ensuring all `[text][reference]` and `[text][]` references have a corresponding `[reference]: URL` definition. Supports options to allow shortcut references and custom allow-lists. Ships TypeScript types and is ESM-only from v5.