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.

lib/md030.mjs

@@ -0,0 +1,57 @@
+// @ts-check
+
+import { addErrorDetailIf } from "../helpers/helpers.cjs";
+import { filterByTypesCached } from "./cache.mjs";
+
+/** @type {import("./markdownlint.mjs").Rule} */
+export default {
+  "names": [ "MD030", "list-marker-space" ],
+  "description": "Spaces after list markers",
+  "tags": [ "ol", "ul", "whitespace" ],
+  "parser": "micromark",
+  "function": function MD030(params, onError) {
+    const ulSingle = Number(params.config.ul_single || 1);
+    const olSingle = Number(params.config.ol_single || 1);
+    const ulMulti = Number(params.config.ul_multi || 1);
+    const olMulti = Number(params.config.ol_multi || 1);
+    for (const list of filterByTypesCached([ "listOrdered", "listUnordered" ])) {
+      const ordered = (list.type === "listOrdered");
+      const listItemPrefixes =
+        list.children.filter((token) => (token.type === "listItemPrefix"));
+      const allSingleLine =
+        (list.endLine - list.startLine + 1) === listItemPrefixes.length;
+      const expectedSpaces = ordered ?
+        (allSingleLine ? olSingle : olMulti) :
+        (allSingleLine ? ulSingle : ulMulti);
+      for (const listItemPrefix of listItemPrefixes) {
+        const range = [
+          listItemPrefix.startColumn,
+          listItemPrefix.endColumn - listItemPrefix.startColumn
+        ];
+        const listItemPrefixWhitespaces = listItemPrefix.children.filter(
+          (token) => (token.type === "listItemPrefixWhitespace")
+        );
+        for (const listItemPrefixWhitespace of listItemPrefixWhitespaces) {
+          const { endColumn, startColumn, startLine } =
+            listItemPrefixWhitespace;
+          const actualSpaces = endColumn - startColumn;
+          const fixInfo = {
+            "editColumn": startColumn,
+            "deleteCount": actualSpaces,
+            "insertText": "".padEnd(expectedSpaces)
+          };
+          addErrorDetailIf(
+            onError,
+            startLine,
+            expectedSpaces,
+            actualSpaces,
+            undefined,
+            undefined,
+            range,
+            fixInfo
+          );
+        }
+      }
+    }
+  }
+};