Added Sleep Sort

Sorts/SleepSort.js

@@ -0,0 +1,18 @@
+/*Sleep sort is a sorting algorithm in which, for every element 
+  to be sorted, we set a timeout for the value of that element.
+  After the timeout is over, we print the value of the element. 
+  Hence the output is printed in the sorted order.
+*/
+
+Array.prototype.sleepSort = function(callback_function) {
+  const arr = [];
+  for (let n of this)
+    setTimeout(() => {
+      arr.push(n);
+      if (this.length === arr.length)
+        callback_function(arr);
+    }, n + 1);
+  return arr;
+};
+ 
+[1, 9, 8, 7, 6, 5, 3, 4, 5, 2, 0].sleepSort(console.log);