support linting dot files

[kellyselden]

path.extname('.lint-todo') === '', so we have to be a little smarter than node to capture these files.

With this change, I can now use https://github.com/kellyselden/textlint-rule-eol-last to lint .lint-todo files with

{
  plugins: {
    '@textlint/text': {
      extensions: ['.lint-todo'],
    },
  },
  rules: {
    'eol-last': true,
  },
};

[azu]

Thanks!

[azu]

Release https://github.com/textlint/textlint/releases/tag/v12.2.4 🎉