Step 1 and Step 2 AI Updates

Small changes to the AI for predicting Step 1 and Step 2 Scores!

We've received more submissions specifically for the most recent NBME for Step 1 and Step 2:
NBME 29, 30, 31 and NBME 18, 20 for Step 2

I wanted to make some updates for Step 3 but we still don't have enough submissions to make a meaningful change yet. We're working on improving our submission process for Step 3 and plan to make some more improvements in the following months