Bump DavidAnson/markdownlint-cli2-action from 17 to 18 (#300)

Bumps [DavidAnson/markdownlint-cli2-action](https://github.com/davidanson/markdownlint-cli2-action) from 17 to 18.
- [Release notes](https://github.com/davidanson/markdownlint-cli2-action/releases)
- [Commits](DavidAnson/markdownlint-cli2-action@v17...v18)

---
updated-dependencies:
- dependency-name: DavidAnson/markdownlint-cli2-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/markdown.yml

@@ -25,6 +25,6 @@ jobs:
       - name: Check out source repository
         uses: actions/checkout@v4
       - name: Markdown Lint
-        uses: DavidAnson/markdownlint-cli2-action@v17
+        uses: DavidAnson/markdownlint-cli2-action@v18
         with:
           globs: '**/*.md'