Fix tokenizer auto_map

tokenizer_config.json

@@ -40,5 +40,11 @@
   "model_max_length": 1000000000000000019884624838656,
   "pad_token": "[PAD]",
   "tokenizer_class": "ChessTokenizer",
-  "unk_token": "[UNK]"
-}
+  "unk_token": "[UNK]",
+  "auto_map": {
+    "AutoTokenizer": [
+      "tokenizer.ChessTokenizer",
+      null
+    ]
+  }
+}