Bump DavidAnson/markdownlint-cli2-action from 18 to 19

Bumps [DavidAnson/markdownlint-cli2-action](https://github.com/davidanson/markdownlint-cli2-action) from 18 to 19.
- [Release notes](https://github.com/davidanson/markdownlint-cli2-action/releases)
- [Commits](DavidAnson/markdownlint-cli2-action@v18...v19)

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

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

Author: dependabot[bot]

.github/workflows/lint.yaml

@@ -22,7 +22,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
-    - uses: DavidAnson/markdownlint-cli2-action@v18
+    - uses: DavidAnson/markdownlint-cli2-action@v20
       with:
         globs: "**/*.md"
   yaml-lint: