Update README.md

README.md

 
 ### Prerequisites
 * Unity Version: 2020.3 LTS
-* Addressables Package: 1.16.16
+* Addressables Package: 1.16.19
 
 ![AllLevels](https://user-images.githubusercontent.com/263776/110165940-42ea3880-7db9-11eb-871c-13e4933e2540.png)
 
 ### More Resources
 * If you’d like to learn more about this demo, and how to use Cloud Content Delivery, [click here](https://www.youtube.com/watch?v=zadjp30LTMs). 
 * If you’d like to watch the full Technical Workshop for Cloud Content Delivery, [click here](https://create.unity3d.com/CCD-technical-workshop?utm_source=demand-gen&utm_medium=video&utm_campaign=asset-links-operate-gms&utm_content=build-vs-buy-ccd-webinar). 
+* If you want to learn more about how to optimize the usage of Addressables, read [this post](https://blog.unity.com/technology/tales-from-the-optimization-trenches-saving-memory-with-addressables) by Patrick DeVarney.