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.

test/rules/rules.cjs

@@ -0,0 +1,30 @@
+// @ts-check
+
+"use strict";
+
+const anyBlockquote = require("./any-blockquote.cjs");
+module.exports.anyBlockquote = anyBlockquote[1];
+
+const everyNLines = require("./every-n-lines.cjs");
+module.exports.everyNLines = everyNLines;
+
+const firstLine = require("./first-line.cjs");
+module.exports.firstLine = firstLine;
+
+const lettersEX = require("./letters-E-X.cjs");
+module.exports.lettersEX = lettersEX;
+
+const lintJavaScript = require("./lint-javascript.cjs");
+module.exports.lintJavaScript = lintJavaScript;
+
+const validateJson = require("./validate-json.cjs");
+module.exports.validateJson = validateJson;
+
+module.exports.all = [
+  ...anyBlockquote,
+  everyNLines,
+  firstLine,
+  lettersEX,
+  lintJavaScript,
+  validateJson
+];