Minimum required version of Node.js to use markdown-lint is now 16.0.0.
.markdownlintrc.js has been renamed to
.markdownlintrc.cjs.
«cjs» file extension should be used now when you include external config using
-c or --config options.
It’s no longer necessary to use require() when including plugins in
remark.plugins config section.
Options listItemIndent and fences have been removed from
remark.stringifySettings section as they duplicated values set by default in
remark-stringify.
No post-upgrade action is required if you use a linter without a custom configuration file.
If you use a custom configuration file, then you should check changes made to .markdownlintrc.js in order to avoid an unexpected behavior.