broken encoding in some stations

with thanks to lis: https://mk.catgirlsfor.science/notes/9en6jb2ig8

src/bahnhofname.gleam

@@ -164,7 +164,8 @@ fn fetch_data() -> Result(String, hackney.Error) {
   let assert Ok(request) = request.from_uri(uri)
   let assert Ok(response) = hackney.send(request)
 
-  Ok(response.body)
+  // some ü are corrupted for some reason
+  Ok(string.replace(response.body, "<EFBFBD>", "ü"))
 }
 
 fn read_csv() -> List(#(String, String)) {