updating DIRECTORY.md

Author: github-actions

DIRECTORY.md

@@ -61,6 +61,7 @@
   * [FindLcm](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/FindLcm.js)
   * [Palindrome](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/Palindrome.js)
   * [PascalTriangle](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/PascalTriangle.js)
+  * [PiApproximationMonteCarlo](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/PiApproximationMonteCarlo.js)
   * [SieveOfEratosthenes](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/SieveOfEratosthenes.js)
 
 ## Recursive