add download instruction

README.md

@@ -50,3 +50,25 @@ configs:
   - split: train
     path: data/train-*
 ---
+
+
+
+## How to download
+1. Set up environment
+```
+pip install datasets tqdm
+wget https://raw.githubusercontent.com/bytedance/coconut_cvpr2024/main/tutorials/download_coconut.py
+```
+
+2. Use the download script to download the COCONut dataset splits.
+```
+python download_coconut.py # default split: relabeled_coco_val
+```
+
+If you want to download the other splits, you can put "coconut_s" or "coconut_b"
+
+```
+python download_coconut.py --split coconut_s --output_dir coconut_s
+```
+
+