Bump rubocop-md from 1.2.0 to 1.2.1 (#379)

Bumps [rubocop-md](https://github.com/rubocop-hq/rubocop-md) from 1.2.0 to 1.2.1.
- [Release notes](https://github.com/rubocop-hq/rubocop-md/releases)
- [Changelog](https://github.com/rubocop/rubocop-md/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop-md@v1.2.0...v1.2.1)

---
updated-dependencies:
- dependency-name: rubocop-md
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Gemfile.lock

@@ -142,7 +142,7 @@ GEM
       rubocop (>= 0.90, < 2)
     rubocop-i18n (3.0.0)
       rubocop (~> 1.0)
-    rubocop-md (1.2.0)
+    rubocop-md (1.2.1)
       rubocop (>= 1.0)
     rubocop-minitest (0.33.0)
       rubocop (>= 1.39, < 2.0)