added @return in documentation of main function

Co-authored-by: realstealthninja <[email protected]>

Author: mjk22071998

greedy_algorithms/binary_addition.cpp

@@ -111,6 +111,7 @@ static void tests() {
 
 /**
  * @brief main function
+ * @returns 0 on successful exit
  */
 int main() {
     tests(); /// To execute tests