old_contents: kthSmallestElementinArray.js
  
new_contents: // Kth Smallest Element in an Array
  
  // Find the kth smallest element in an unsorted array. Note that it is the kth smallest element in the sorted order,
  // not the kth distinct element.
  
  // For example,
  // Given [3,2,1,5,6,4] and k = 2, return 2.
  
  // Note:
  // You may assume k is always valid, 1 ≤ k ≤ array's length.
  
  
subject: add desc