I would not have guessed that the base input data processing would have been filed under 'steps'. But now I kinda see how you are working, but I admit I'm not the target audience.
If you want this to really take off for people outside of a very, very specific class of researchers... setup an example on your landing page that calls to a local JSON of user prompts/answers/rejects finetuning a llama model with your datadreamer.steps.JSONDataSource into the loader. Or, a txt file with the system/user/assistant prompts tagged and examples given. Yes, your 'lines of code' for your frontpage example may grow a bit!
Maybe there are a lot of 'ML researchers' that are used to the type of super-abstract OOP API, load-it-from-huggingface-scheme-people you are targeting but also know that there are a ton that aren't.