Update rubocop-md requirement from ~> 0.3.1 to ~> 0.4.0 (#108)
Update rubocop-md requirement from ~> 0.3.1 to ~> 0.4.0 (#108)

Updates the requirements on [rubocop-md](https://github.com/rubocop-hq/rubocop-md) to permit the latest version.
- [Release notes](https://github.com/rubocop-hq/rubocop-md/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop-md/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop-hq/rubocop-md/compare/v0.3.1...v0.4.0)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>

Co-authored-by: dependabot-preview[bot] <6a4c1c4838f800d1998274cd5234e1f65c55e90c@users.noreply.github.com>
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