pref: optimize the count vowels algo

simplify the algo by using regex and String.prototype.match method, and modified the JS Doc

String/CountVowels.js

@@ -1,25 +1,21 @@
 /**
  * @function countVowels
  * @description Given a string of words or phrases, count the number of vowels.
- * @param {String} url - The input string
- * @return {Number} count
+ * @param {String} str - The input string
+ * @return {Number} - The number of vowel 
  * @example countVowels("ABCDE") => 2
  * @example countVowels("Hello") => 2
  */
 
 const countVowels = (str) => {
   if (typeof str !== 'string') {
-    throw new TypeError('Input should be a string')
+    throw new TypeError('Input should be a string');
   }
-  const vowels = new Set(['a', 'e', 'i', 'o', 'u'])
-  let count = 0
-  for (let i = 0; i < str.length; i++) {
-    const char = str[i].toLowerCase()
-    if (vowels.has(char)) {
-      count++
-    }
-  }
-  return count
+
+  const vowelRegex = /[aeiou]/gi;
+  const vowelsArray = str.match(vowelRegex) || [];
+
+  return vowelsArray.length;
 }
 
-export { countVowels }
+export { countVowels };