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/webpack.config.mjs

@@ -0,0 +1,97 @@
+// @ts-check
+
+import { createRequire } from "node:module";
+const require = createRequire(import.meta.url);
+import webpack from "webpack";
+import TerserPlugin from "terser-webpack-plugin";
+import { __dirname, importWithTypeJson } from "../test/esm-helpers.mjs";
+const libraryPackageJson = await importWithTypeJson(import.meta, "../package.json");
+const nodeModulePrefixRe = /^node:/u;
+
+// eslint-disable-next-line jsdoc/require-jsdoc
+function config(options) {
+  const { entry, filename, mode, optimization, packageJson } = options;
+  const { name, version, homepage, license } = packageJson;
+  return {
+    "devtool": false,
+    "entry": entry,
+    "externals": {
+      "markdown-it": "markdownit"
+    },
+    "mode": mode,
+    "module": {
+      "rules": [
+        {
+          "test": /\.[cm]?js$/,
+          "exclude": /node_modules/
+        }
+      ]
+    },
+    "name": name,
+    "optimization": optimization,
+    "output": {
+      "filename": filename,
+      "library": {
+        "name": name.replace(/(-\w)/g, (m) => m.slice(1).toUpperCase()),
+        "type": "var"
+      },
+      "path": __dirname(import.meta)
+    },
+    "plugins": [
+      new webpack.NormalModuleReplacementPlugin(
+        nodeModulePrefixRe,
+        (resource) => {
+          const module = resource.request.replace(nodeModulePrefixRe, "");
+          resource.request = module;
+        }
+      ),
+      new webpack.BannerPlugin({
+        "banner": `${name} ${version} ${homepage} @license ${license}`
+      })
+    ],
+    "resolve": {
+      "fallback": {
+        "fs": false,
+        "os": false,
+        "path": false,
+        "util": false,
+        "module": require.resolve("./module-stub.cjs")
+      }
+    }
+  };
+}
+
+const modeDevelopment = {
+  "mode": "development"
+};
+const modeProduction = {
+  "mode": "production",
+  "optimization": {
+    "minimizer": [
+      new TerserPlugin({
+        "extractComments": false,
+        "terserOptions": {
+          "compress": {
+            "passes": 2
+          }
+        }
+      })
+    ]
+  }
+};
+const entryLibrary = {
+  "entry": "./browser-exports.mjs",
+  "packageJson": libraryPackageJson
+};
+export default [
+  config({
+    ...entryLibrary,
+    ...modeDevelopment,
+    "filename": "markdownlint-browser.js"
+  }),
+  config({
+    ...entryLibrary,
+    ...modeProduction,
+    "filename": "markdownlint-browser.min.js"
+  })
+];