Update README.md

Tweaking unit summary table to be closer to the current plan and show date for unit 3

Author: johnowhitaker

README.md

@@ -22,8 +22,8 @@ Register via the **[signup form](https://huggingface.us17.list-manage.com/subscr
 |---------------|----------------------------------------------------------|----------------------------------------------------------------------------------------------------------|
 | November 28, 2022  | [An Introduction to Diffusion Models](https://github.com/huggingface/diffusion-models-class/tree/main/unit1)| Introduction to Diffusers and Diffusion Models From Scratch |
 | December 12, 2022  | [Fine-Tuning and Guidance](https://github.com/huggingface/diffusion-models-class/tree/main/unit2) | Fine-Tuning a Diffusion Model on New Data and Adding Guidance |
-| TBA  | Stable Diffusion Intro | Exploring a Powerful Text-Conditioned Latent Diffusion Model |
-| TBA  | Stable Diffusion Deep Dive | Fine-Tuning, Sampling Tricks and Custom Pipelines |
+| December 19, 2022  | Stable Diffusion | Exploring a Powerful Text-Conditioned Latent Diffusion Model |
+| January 2023 (TBC)  | Doing More with Diffusion | Advanced Techniques to Take Diffusion Further |
 
 More information coming soon!