Hello, first time contributor here!

What does this PR do?

I was working through this great notebook and noticed a typo along with some areas that I felt needed clarifying in the code. The changes were mostly comments and a typo.

I fixed the "thresold" to "threshold" typo inside thesemantic_cache class.

In thesemantic_cache class, I tried to reduce the ambiguity of the code by adding a few clarifying comments since the class was the central point of the notebook. These additions aim to assist first-time readers in understanding the FAISS implementation.

These changes include adding clarification on:

• The definitions of theD andI arrays that were returned fromindex.search()
• Meaning ofnprobe
• Adding comments on the meaning of the If conditions

I didn't want to overcomplicate the explanations as the contribution guide says, but I did want to give context that I thought could help a reader out.

Who can review?

@MKhalusova I would appreciate the review!