Add birefnet model_type and tag (#22)

- Add birefnet model_type and tag (73a6204a2a339c65a5a010af4619a0612547c6c0)


Co-authored-by: Joshua <[email protected]>

config.json

@@ -16,5 +16,6 @@
       "type": "image"
     }
   },
-  "bb_pretrained": false
+  "bb_pretrained": false,
+  "model_type": "birefnet"
 }