Updates the tokenizer configuration file (#16)

- Adds tokenizer_config.json file (5188f339e0fd19c8a007f5a48b7519c63088e467)

tokenizer_config.json

@@ -1,3 +1 @@
-{
-  "do_lower_case": false
-}
+{"do_lower_case": false, "model_max_length": 512}