chore: Remove duplicate DigitSum algorithm (#873)

* Auto-update DIRECTORY.md

* chore: remove duplicate algorithm

* Auto-update DIRECTORY.md

* chore: remove duplicate algorithm tests

Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>

Maths/DigitSum.js

@@ -1,16 +0,0 @@
-// program to find sum of digits of a number
-
-// function which would calculate sum and return it
-const digitSum = (num) => {
-  // sum will store sum of digits of a number
-  let sum = 0
-  // while will run until num become 0
-  while (num) {
-    sum += num % 10
-    num = parseInt(num / 10)
-  }
-
-  return sum
-}
-
-export { digitSum }

Maths/test/DigitSum.test.js

@@ -1,11 +0,0 @@
-import { digitSum } from '../DigitSum'
-
-describe('digitSum', () => {
-  it('is a function', () => {
-    expect(typeof digitSum).toEqual('function')
-  })
-  it('should return the sum of digits of a given number', () => {
-    const sumOfNumber = digitSum(12345)
-    expect(sumOfNumber).toBe(15)
-  })
-})