Convert to ESM

src/wait.js

@@ -1,17 +1,13 @@
 /**
- * Wait for a number of milliseconds.
+ * Waits for a number of milliseconds.
  *
  * @param {number} milliseconds The number of milliseconds to wait.
  * @returns {Promise<string>} Resolves with 'done!' after the wait is over.
  */
-async function wait(milliseconds) {
-  return new Promise(resolve => {
-    if (isNaN(milliseconds)) {
-      throw new Error('milliseconds not a number')
-    }
+export async function wait(milliseconds) {
+  return new Promise((resolve) => {
+    if (isNaN(milliseconds)) throw new Error('milliseconds is not a number')
 
     setTimeout(() => resolve('done!'), milliseconds)
   })
 }
-
-module.exports = { wait }