Allow specifying template_name and dataset_name

[nbardy]

Makes a few changes:

• This modifies the code to allow loading a template by name.
• Adds additional templates for generation
• Allows specifying dataset_name

[nbardy]

@thooton Curious if you're still working on this project?

There is a lot of data on huggingface from this repo. Would be exciting to add some variety.

Might fork this if you're not thinking about maintaining it.