feat: Update SS with evals for Grade 5-12

[adnanrhussain]

This PR extends the Sentence Structure Evaluator (notebook) to support additional grades (5 to 12) beyond the existing grades (3 & 4).

Status: This PR is currently under internal review and testing, before it is ready to be released

[gary-mu]

Love this integration of grade 5-12.
2 comments:

1. Can we also add Ariena as reviewer? She's not a member of this repo, so I can't add her
2. Can we add test result? I think running test passages and paste result can be sufficient.

[aychi1]

Overall LGTM. Two small callouts:

• Some duplicative fields between Gr 3-4 and 5-12 (e.g. num_compound vs num_compound_sentences, perc_simple_sentences vs. perc_simple, etc).
• Prompt definition for simple sentence is not exactly the same between Noah's version and Wayne's version, and this isn't captured in the PR. Noah's version specifically mentions that simple sentences with relative clauses still count as simple. It likely won't make a big difference, but just documenting here that this is a known departure.

[aychi1]

Overall LGTM. Commented on some non-blocking nits.

[aychi1]

Just curious, is there a reason why we have both num_compound_sentences (line 173) and num_compound (line 259)? Asking bc I noticed that the definition is the same across both Grades 3-4 vs. 5-12 evals.

On a similar note, the definition for Simple Sentences is slightly different between Noah's prompt vs. Wayne's prompt. It likely does not make a big difference, but just want to call out that we've never tested.

[gary-mu]

I think it might be good to keep the prompt for each version as untouched as possible as we know LLM output is sensitive to prompt changes.