Fix YAML frontmatter and variable name

- Remove comment line from YAML frontmatter
- Fix variable name: ad -> adata
- Add shape info to summary

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -1,5 +1,4 @@
 ---
-# 1. Metadata Block
 license: mit
 task_categories:
 - tabular-classification
@@ -14,10 +13,13 @@ size_categories:
 # binary-atac-tutorial-data
 
 ## Dataset Summary
-This dataset contains binary accessibility values for 1154611 CREs in 222 cell types. The original source of this data is CATlas (https://decoder-genetics.wustl.edu/catlasv1/humanenhancer/data/cCRE_by_cell_type/). For more details, see https://decoder-genetics.wustl.edu/catlasv1/catlas_humanenhancer/#!/. This version of the dataset is used in gReLU tutorial 2 (https://github.com/Genentech/gReLU/blob/main/docs/tutorials/2_finetune.ipynb).
+This dataset contains binary accessibility values for 1,154,611 CREs in 222 cell types. The original source of this data is CATlas (https://decoder-genetics.wustl.edu/catlasv1/humanenhancer/data/cCRE_by_cell_type/). For more details, see https://decoder-genetics.wustl.edu/catlasv1/catlas_humanenhancer/#!/. This version of the dataset is used in gReLU tutorial 2 (https://github.com/Genentech/gReLU/blob/main/docs/tutorials/2_finetune.ipynb).
 
 ## Dataset Structure
 
+- **Shape:** 222 cell types × 1,154,611 CREs
+- **Genome build:** hg38
+
 ### Data Fields
 In `.obs`:
 
@@ -33,8 +35,8 @@ In `.var`:
 | `start` | int | Genomic start position (hg38) |
 | `end` | int | Genomic end position (hg38) |
 | `Class` | category | CRE class |
-       
-`.X` is a binary accessibility matrix of shape (222 × 1154611) in Compressed Sparse Row format.
+
+`.X` is a binary accessibility matrix of shape (222 × 1,154,611) in Compressed Sparse Row format.
 
 ## Usage
 
@@ -47,5 +49,5 @@ file_path = hf_hub_download(
     repo_type="dataset",
     filename="data.h5ad"
 )
-ad = anndata.read_h5ad(file_path)
-```
+adata = anndata.read_h5ad(file_path)
+```