Revise LLM-assisted extraction project details

[dlebauer]

[set as 'draft' pending approval from @koolgax99

Update and (re)focus and rename the “LLM-Assisted Extraction of Agronomic Experiments into BETYdb.”

Key changes:

• Change scope from BETYdb entry (not the focus) to 'consistent w/ BETYdb upload template`.
• Make supervised fine-tuning a key outcome; as I understand it, this is what really leverages the existing PDF to structured-data mappings from BETYdb and ForC.
• Update prerequisites to focus on Python/NLP/ML rather than R Shiny.
• Set difficulty High (not med or high).

Removed out of date projects. (This was part of #151; not sure where they re-appeared).

[koolgax99]

@dlebauer Thanks for the changes! The PR looks good to me.

Can we add the link to ForC?

[dlebauer]

Can we add the link to ForC?

Done, thanks!