Convert dataset sizes from base 2 to base 10 in the dataset card

Convert dataset sizes from base 2 (MiB) to base 10 (MB) in the dataset card, as it is the case in the dataset viewer.
See: https://github.com/huggingface/datasets/issues/5708

README.md

@@ -208,7 +208,7 @@ AdvGLUE deviates from the GLUE dataset, which has a base language of English.
 
 #### default
 
-- **Size of downloaded dataset files:** 198 KB
+- **Size of downloaded dataset files:** 202.75 KB
 - **Example**:
 ```python
 >>> datasets.load_dataset('adv_glue', 'adv_sst2')['validation'][0]