A GitHub package called eslint-markdown extends ESLint's capabilities to include Markdown file linting. The tool provides additional rules that work alongside ESLint's built-in Markdown support through the @eslint/markdown package. Developers can now apply consistent code quality standards to documentation files that live alongside their JavaScript code.

Unlike ESLint's native Markdown rules, this plugin fills gaps in the linting ecosystem. The maintainers explicitly state that no rule overlap exists between the two, making them complementary rather than competing tools. Users should install both packages to get comprehensive coverage across all their project files.

The plugin supports standard ESLint configuration patterns, allowing teams to integrate Markdown linting into existing workflows without major tooling changes. Documentation includes installation guides, configuration examples, and migration paths from other Markdown linting solutions.

For JavaScript-heavy projects where documentation lives in Markdown, this creates a unified linting experience. The MIT-licensed package could streamline code review processes by catching formatting inconsistencies before pull requests get submitted.