Add simple scaffolding for profiling and timing execution.

test/profile-fixture.mjs

@@ -0,0 +1,18 @@
+import { readFile } from "node:fs/promises";
+import library from "../lib/markdownlint.js";
+const markdownlint = library.promises.markdownlint;
+
+const strings = {
+  "CONTRIBUTING": await readFile("CONTRIBUTING.md", "utf8"),
+  "README": await readFile("README.md", "utf8"),
+  "CustomRules": await readFile("./doc/CustomRules.md", "utf8"),
+  "Prettier": await readFile("./doc/Prettier.md", "utf8"),
+  "Rules": await readFile("./doc/Rules.md", "utf8")
+};
+
+const start = new Date();
+for (let i = 0; i < 250; i++) {
+  await markdownlint({strings});
+}
+const end = new Date();
+console.log(`Elapsed: ${end - start}`);