Update wave_sort.cpp

Author: Swastyy

sorting/wave_sort.cpp

@@ -1,6 +1,6 @@
 /**
  * @file
- * @brief Implementation of [Wave sort] algorithm
+ * @brief Implementation of [Wave sort](https://www.geeksforgeeks.org/sort-array-wave-form-2/) algorithm
  * @details
  * Wave Sort is a sorting algorithm that works in \f$O(nlogn)\f$ time assuming
  * the sort function used works in \f$O(nlogn)\f$ time.