Having worked through chapter 3 of Sebastian Raschka's book "Build a Large Language Model (from Scratch)", and spent some time digesting the concepts it introduced (most recently in my post on the complexity of self-attention at scale), it's time for chapter 4. I've read it through in its entirety, and rather than working through it section-by-section in order, like I did with the last one, I think I'm going to jump around a bit, covering each new concept and how I wrapped my head around it s...