Updates the tokenizer configuration file (#3)

- Adds tokenizer_config.json file (f2bb6ba08dc228f0b28f24194f82fcf726bc6c83)

tokenizer_config.json

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