Add brief comment

metroidgen.py

@@ -697,7 +697,7 @@ class MetroidState:
         for i in range(17):
             j = i * 8
             k = j + 8
-            word = self.fullbitfield[j:k][::-1]
+            word = self.fullbitfield[j:k][::-1] # I thought [j:k:-1] should work but it doesn't
             newBitfield.append(word)
         decChecksum = sum([int(x, 2) for x in newBitfield])
         bitfield = "".join(newBitfield)