chore(deps): update davidanson/markdownlint-cli2-action action to v18 (#64)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/ci.yml

@@ -22,7 +22,7 @@ jobs:
       - name: Check out code
         uses: actions/checkout@v4
       - name: Run Markdown Lint
-        uses: DavidAnson/markdownlint-cli2-action@v17
+        uses: DavidAnson/markdownlint-cli2-action@v18
         with:
           globs: "**/*.md"
   json: