chore(deps): update dependency markdownlint-cli2 to v0.20.0 (#31)

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

Author: renovate[bot]

package-lock.json

@@ -64,7 +64,7 @@
     "husky": "9.1.7",
     "knip": "5.71.0",
     "lint-staged": "16.2.7",
-    "markdownlint-cli2": "0.19.1",
+    "markdownlint-cli2": "0.20.0",
     "markdownlint-cli2-formatter-pretty": "0.0.9",
     "npm-run-all2": "8.0.4",
     "prettier": "3.7.4",