Markdown Link Checker
This is a textlint rule that validates relative links in markdown documents. First it verifies that relative links belong to a file, then it verifies the anchor in the link exists in a header id or by using the github-slugger.
Usage
First Install Textlint, then use the command textlint --rule @package-tucker/textlint-linkcheck-relative-ids <path_to_markdown_files> -f pretty-error
Docusaurus Usage
This textlint rule was created to test relative links within Docusaurus projects. To implement into Docusaurus, add the script "verify": "textlint --rule @package-tucker/textlint-linkcheck-relative-ids ./docs/ -f pretty-error" to the scripts section of the package.json file. Then run the command yarn verify to check all relative links within the Docusaurus project. All relative links will be verified, including anchored links with explicit ids.