Typo in y2023 d17 walkthrough

[Alexey Ismagilov]

In y2023 d17 pt2 walkthrough should be

-    for _ in range(1, 3 + 1):
+    for i in range(1, stop + 1):

instead of

-    for _ in range(1, 3 + 1):
+    for i in range(start, stop + 1):

[Marco Bonelli]

Thank you again for spotting the typo! Fixed in d41d8d1.