Fix repo contentUrl: remove /tree/main suffix

croissant.json

@@ -79,7 +79,7 @@
       "@id": "repo",
       "name": "repo",
       "description": "Hugging Face dataset repository serving as the root container for all distribution files.",
-      "contentUrl": "https://huggingface.co/datasets/mysigner/MySign/tree/main",
+      "contentUrl": "https://huggingface.co/datasets/mysigner/MySign",
       "encodingFormat": "git+https",
       "sha256": "main"
     },