Doc update

src/AoC_2023/Dazbo's_Advent_of_Code_2023.ipynb

@@ -4673,7 +4673,7 @@
     "  differnce of the cumulative sums of their col indexes.\n",
     "\n",
     "This approach is efficient because to obtain a vertical or horizontal distance between two points, \n",
-    "we only need to retrieve two index values from the array, and subtract one from the other."
+    "we only need to retrieve two index values from the array, and subtract one from the other. The cumulative sum array is ideal when we need to frequently obtain the sum of a range."
    ]
   },
   {