update aicrowd.json

aicrowd.json

@@ -2,8 +2,9 @@
     "challenge_id": "evaluations-api-music-demixing",
     "grader_id": "evaluations-api-music-demixing",
     "authors": [
-        "yoyololicon"
+        "yoyololicon",
+        "kinwaicheuk"
     ],
-    "description": "Demucs with separated decoders",
+    "description": "Model fusion with Demucs, XUMX, and UNet with attention",
     "external_dataset_used": false
 }
\ No newline at end of file