Enable ESLint rule unicorn/no-array-for-each, auto-fix all violations, manually address new issues for ~4% time reduction measured via profile-fixture.mjs on Apple Silicon M1.

lib/md005.js

@@ -11,12 +11,12 @@ module.exports = {
   "description": "Inconsistent indentation for list items at the same level",
   "tags": [ "bullet", "ul", "indentation" ],
   "function": function MD005(params, onError) {
-    flattenedLists().forEach((list) => {
+    for (const list of flattenedLists()) {
       const expectedIndent = list.indent;
       let expectedEnd = 0;
       let actualEnd = -1;
       let endMatching = false;
-      list.items.forEach((item) => {
+      for (const item of list.items) {
         const { line, lineNumber } = item;
         const actualIndent = indentFor(item);
         let match = null;
@@ -63,7 +63,7 @@ module.exports = {
             }
           }
         }
-      });
-    });
+      }
+    }
   }
 };