Fix FilterFiles: add cr:FileObject @id =repo + containedIn for both FileSets

croissant.json

@@ -136,11 +136,21 @@
     }
   ],
   "distribution": [
+    {
+      "@type": "cr:FileObject",
+      "@id": "repo",
+      "name": "repo",
+      "description": "The Hugging Face git repository hosting the Apple-Pi dataset.",
+      "contentUrl": "https://huggingface.co/datasets/AnonymousSubmitt/apple-pi",
+      "encodingFormat": "git+https",
+      "sha256": "https://github.com/mlcommons/croissant/issues/80"
+    },
     {
       "@type": "cr:FileSet",
       "@id": "sim_subset",
       "name": "sim_subset",
       "description": "Simulation cases. Each case is a folder containing rendered video frames, instance segmentation, depth, mask, velocity, and physics annotations.",
+      "containedIn": {"@id": "repo"},
       "encodingFormat": "application/octet-stream",
       "includes": "sim_subset/**/*"
     },
@@ -149,6 +159,7 @@
       "@id": "realworld_subset",
       "name": "realworld_subset",
       "description": "Realworld cases. Each case is a folder containing a video clip, instance segmentation, mask, velocity reference, and physics annotations.",
+      "containedIn": {"@id": "repo"},
       "encodingFormat": "application/octet-stream",
       "includes": "realworld_subset/**/*"
     }