Bump markdownlint-cli from 0.39.0 to 0.40.0

Bumps [markdownlint-cli](https://github.com/igorshubovych/markdownlint-cli) from 0.39.0 to 0.40.0.
- [Release notes](https://github.com/igorshubovych/markdownlint-cli/releases)
- [Commits](igorshubovych/markdownlint-cli@v0.39.0...v0.40.0)

---
updated-dependencies:
- dependency-name: markdownlint-cli
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -44,7 +44,7 @@
     "gravatar-favicons": "^3.0.0",
     "highlight.js": "^11.0.1",
     "jsonfeed-to-atom": "^1.2.4",
-    "markdownlint-cli": "^0.39.0",
+    "markdownlint-cli": "^0.40.0",
     "mine.css": "^9.0.1",
     "npm-run-all2": "^6.0.0",
     "p-map": "^7.0.0",