[Improvement] Added example for Binary Search in Swift

client/src/pages/guide/english/algorithms/search-algorithms/binary-search/index.md

@@ -286,6 +286,25 @@ int binarySearch(int arr[], int start, int end, int x)
 }
 ```
 
+### Example in Swift
+```Swift
+func binarySearch(for number: Int, in numbers: [Int]) -> Int? {
+    var lowerBound = 0
+    var upperBound = numbers.count
+    while lowerBound < upperBound {
+        let index = lowerBound + (upperBound - lowerBound) / 2
+        if numbers[index] == number {
+            return index // we found the given number at this index
+        } else if numbers[index] < number {
+            lowerBound = index + 1
+        } else {
+            upperBound = index
+        }
+    }
+    return nil // the given number was not found
+}
+```
+
 ### More Information
 * [Binary search (YouTube video)](https://youtu.be/P3YID7liBug)
 * [Binary Search - CS50](https://www.youtube.com/watch?v=5xlIPT1FRcA)