Update markdownlint version (markdownlint-cli2 v0.6.0, markdownlint v0.27.0).

v9.0.0

Update documentation and examples to reference @v9.

Add "separator" input, update dependencies

v8.0.0

Update documentation and examples to reference @v8.

Update markdownlint version (markdownlint-cli2 v0.5.1, markdownlint v0.26.2).

v7.0.0

Regenerate index.js after dependency updates.

Add "command" input (supporting "config" and "fix"), update dependencies

v6.0.0

Update documentation and example to reference @v6.

Add support for title/file/line/column annotations when reporting errors

v5.1.0

Convert annotation properties startLine/startColumn to the correct ty…

Update markdownlint version (markdownlint-cli2 v0.4.0, markdownlint v0.25.1)

v5.0.0

Update Action configuration to use Node 16.

Update markdownlint-cli2 version

v4.0.0

Update documentation and example to reference @v4.

Update markdownlint-cli2 version

v3.0.0

Update documentation and example to reference @v3.

Update markdownlint

v2.0.0

Update documentation and example to reference @v2.

Trivial improvements

v1.0.1

Add test script to test workflow.