Update config.json

config.json

@@ -1,8 +1,8 @@
 {
-  "model_type": "custom_gpt",
+  "model_type": "challenger",
   "vocab_size": 100288,
   "n_layer": 16,
   "n_head": 16,
   "n_embd": 1536,
-  "architectures": ["CustomGPTModel"]
+  "architectures": ["ChallengerModel"]
 }