Remove a copy-paste sentence in dataset cards (#4281)

Commit from https://github.com/huggingface/datasets/commit/bf6108b8e09fae44787a6a7b20b8718c6e86dd7f

README.md

@@ -73,8 +73,6 @@ Books are a rich source of both fine-grained information, how a character, an ob
 
 ## Dataset Structure
 
-We show detailed information for up to 5 configurations of the dataset.
-
 ### Data Instances
 
 #### plain_text