Clarify read_folder return type and fix demo

[ASR134]

Currently, the read_folder function returns a concatenated Dataframe, while the demo file iterates over it as if it were a list of Dataframes. This can be confusing for the users.

I propose updating the read_folder function to return a list of Dataframes and adjusting the docstring/demo accordingly.

I have local fix ready and can open a pull request if this appoach is applicable.

[Kritika11052005]

I’d like to take this issue.

I’ll focus on clarifying the return type of read_folder, improving docstrings and examples, and fixing the demo to reflect the actual behavior. I’ll also review edge cases and add tests where appropriate to avoid ambiguity for users.

Open to feedback and suggestions before finalizing changes.