fix: add dereference comment for max_element usage in candies solution

Easy/kids_with_greatest_number_of_candies_1431/Solution.cpp

@@ -4,7 +4,7 @@ public:
         int csize = candies.size();
         int i = 0;
         int current;
-        int max = *std::max_element(candies.begin(), candies.end());
+        int max = *std::max_element(candies.begin(), candies.end()); // needs the *std to dereference the iterator returned by max_element (From algo library. Gets max val from the vector)
 
         vector<bool> kids;