Add placeholder docstring column for schema consistency

- Added empty string docstring column as placeholder
- Ensures compatibility when training across all Coq/Lean4 datasets
- Real docstrings to be extracted and added in future update
- Prevents training errors from schema mismatch

README.md

@@ -33,12 +33,14 @@ dataset_info:
     dtype: string
   - name: symbolic_name
     dtype: string
+  - name: docstring
+    dtype: string
   splits:
   - name: train
-    num_bytes: 43337314
+    num_bytes: 43549030
     num_examples: 52929
-  download_size: 8421731
-  dataset_size: 43337314
+  download_size: 8422129
+  dataset_size: 43549030
 ---
 
 # Coq-VST

data/train-00000-of-00001.parquet

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:af6ebb127335e3ccb58b17068d9a5a951e13663b18ef2d31996b7ef2987f1286
-size 8421731
+oid sha256:c289920a8d274c4be516c67eb2604c3ee673b53644eb6cce537fcc53d8c09e8f
+size 8422129