Bump markdownlint-cli2 from 0.18.1 to 0.20.0 in /doc

Bumps [markdownlint-cli2](https://github.com/DavidAnson/markdownlint-cli2) from 0.18.1 to 0.20.0.
- [Changelog](https://github.com/DavidAnson/markdownlint-cli2/blob/main/CHANGELOG.md)
- [Commits](DavidAnson/markdownlint-cli2@v0.18.1...v0.20.0)

---
updated-dependencies:
- dependency-name: markdownlint-cli2
  dependency-version: 0.20.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

doc/package-lock.json

@@ -5,7 +5,7 @@
     "node": ">=20.0.0"
   },
   "devDependencies": {
-    "markdownlint-cli2": "0.18.1"
+    "markdownlint-cli2": "0.20.0"
   },
   "scripts": {
     "build": "npx markdownlint-cli2"