updating DIRECTORY.md

Author: github-actions

DIRECTORY.md

@@ -138,6 +138,7 @@
   * [FindLcm](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/FindLcm.js)
   * [GridGet](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/GridGet.js)
   * [IsDivisible](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/IsDivisible.js)
+  * [IsEven](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/IsEven.js)
   * [isOdd](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/isOdd.js)
   * [Mandelbrot](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/Mandelbrot.js)
   * [MatrixExponentiationRecursive](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/MatrixExponentiationRecursive.js)
@@ -176,6 +177,7 @@
     * [FindLcm](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/test/FindLcm.test.js)
     * [GridGet](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/test/GridGet.test.js)
     * [IsDivisible](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/test/IsDivisible.test.js)
+    * [IsEven](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/test/IsEven.test.js)
     * [MeanSquareError](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/test/MeanSquareError.test.js)
     * [ModularBinaryExponentiationRecursive](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/test/ModularBinaryExponentiationRecursive.test.js)
     * [NumberOfDigits](https://github.com/TheAlgorithms/Javascript/blob/master/Maths/test/NumberOfDigits.test.js)