Issues-126 - Fixed formatting, jsdoc and example for JavaScript/ES6 (#127)

* Issues-126 - Fixed formatting, jsdoc and non-working example for JavaScript/ES6

* Issues-126 - Fixed jsdoc

01_introduction_to_algorithms/javascript/01_binary_search.js

@@ -1,22 +1,28 @@
-'use strict';
+"use strict";
 
+/**
+ * Searches recursively number from the list
+ * @param {Array} list Source array
+ * @param {number} item Search item
+ * @returns {(number|null)} Number if the value is found or NULL otherwise
+ */
 function binary_search(list, item) {
   let low = 0;
   let high = list.length - 1;
-  
+
   while (low <= high) {
-    let mid = Math.floor((low + high) / 2);
-    let guess = list[mid];
-    if (guess === item) {
+    const mid = Math.floor((low + high) / 2);
+    const guess = list[mid];
+
+    if (guess === item) {
       return mid;
-    }
-    if (guess > item) {
+    } else if (guess > item) {
       high = mid - 1;
     } else {
       low = mid + 1;
     }
   }
-  
+
   return null;
 }