merge: Add test case to the Exponential Search Algorithm (TheAlgorithms#1040)

* Add test case to the Exponential Search Algorithm

* Updated Documentation in README.md

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

Author: Ankush263

Search/test/ExponentialSearch.test.js

@@ -0,0 +1,15 @@
+import { exponentialSearch } from '../ExponentialSearch'
+
+test('The Exponential Search of the Array [2, 3, 4, 10, 40, 65, 78, 100] is 6 where the value = 78', () => {
+  const arr = [2, 3, 4, 10, 40, 65, 78, 100]
+  const value = 78
+  const result = exponentialSearch(arr, arr.length, value)
+  expect(result).toEqual(6)
+})
+
+test('The Exponential Search of the Array [2, 3, 4, 10, 40, 65, 78, 100] is -1 where the value = 178', () => {
+  const arr = [2, 3, 4, 10, 40, 65, 78, 100]
+  const value = 178
+  const result = exponentialSearch(arr, arr.length, value)
+  expect(result).toEqual(-1)
+})