Convert markdownlint library to an ECMAScript module, replace markdownlint-micromark with micromark, stop publishing (large) markdownlint-browser.js, see https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c for guidance.

example/Gruntfile.cjs

@@ -0,0 +1,28 @@
+// @ts-check
+
+"use strict";
+
+module.exports = function wrapper(grunt) {
+  grunt.initConfig({
+    "markdownlint": {
+      "example": {
+        "src": [ "*.md" ]
+      }
+    }
+  });
+
+  grunt.registerMultiTask("markdownlint", function task() {
+    const done = this.async();
+    import("markdownlint").then(({ "default": markdownlint }) => {
+      markdownlint(
+        { "files": this.filesSrc },
+        function callback(err, result) {
+          const resultString = err || ((result || "").toString());
+          if (resultString) {
+            grunt.fail.warn("\n" + resultString + "\n");
+          }
+          done(!err || !resultString);
+        });
+    }).catch(done);
+  });
+};