Add term clarification to lesson

[kjallen]

This could go in several places in the lesson or a reference to the glossary

Short explanation or description to address:

• ChatGPT / LLMs
• Image generative models / GANs
• Acronym demystification (AI, ML, LLM, NLP, GAN, NN, DL, etc...)

Originally posted by @kjallen in #82 (comment)