Update added_tokens.json

added_tokens.json

@@ -20,5 +20,7 @@
   "<|video_pad|>": 151656,
   "<|vision_end|>": 151653,
   "<|vision_pad|>": 151654,
-  "<|vision_start|>": 151652
+  "<|vision_start|>": 151652,
+  "<artifact>": 151665,
+  "</artifact>": 151666
 }