docs: fix maxGridRingSize doc

Author: isaacbrodsky

website/docs/api/traversal.mdx

@@ -326,7 +326,7 @@ grid distance `k` away from an origin, which is `6*k` if `k > 0` and `1` if `k =
 <TabItem value="c">
 
 ```c
-H3Error maxGridRingSize(int k, H3Index* out);
+H3Error maxGridRingSize(int k, int64_t* out);
 ```