fix: use .markdownlint-cli2.mjs for the configuration file

.markdownlint-cli2.mjs

@@ -0,0 +1,15 @@
+import relativeLinksRule from "./src/index.js"
+
+const config = {
+  config: {
+    "extends": "markdownlint/style/prettier",
+    default: true,
+    "relative-links": true,
+    "no-inline-html": false,
+  },
+  globs: ["**/*.md"],
+  ignores: ["**/node_modules", "**/test/fixtures/**"],
+  customRules: [relativeLinksRule],
+}
+
+export default config