Update readme

README.md

@@ -23,5 +23,10 @@ I provide both English and Vietnamese `.tsv` files. For the English one, one can
 - https://huggingface.co/datasets/conceptual_captions
 - https://github.com/google-research-datasets/conceptual-captions
 
+To download the dataset, one can use the tool:
+- https://github.com/rom1504/img2dataset/blob/main/dataset_examples/cc3m.md
+
+Or just iterate line by line (`url<tab>caption`)
+
 ⚠ Note:
 - Some of image urls might die over the time ([liuhaotian/LLaVA-CC3M-Pretrain-595K](https://huggingface.co/datasets/liuhaotian/LLaVA-CC3M-Pretrain-595K) reported that 15% of original dataset are inaccessible). I'm not responsible for them.