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.

demo/module-stub.cjs

@@ -0,0 +1,8 @@
+// @ts-check
+
+"use strict";
+
+module.exports = {
+  // @ts-ignore
+  "createRequire": () => require
+};