Update README.md

Add PebbleOS documentation

README.md

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 This repository contains the source code of PebbleOS.
 
+## How PebbleOS works
+Read more in the very detailed [PebbleOS architecture presentation](https://docs.google.com/presentation/d/1wfyBRwbrv5YtSnvNRnEPz5tRx9y7VGcFsuHbi1X-D7I/edit?usp=sharing)
+
+Then read this [presentation on how PebbleOS works](https://docs.google.com/presentation/d/1M--yoEJBO-uckvY5CTFfHT4srw6RCj9RTGT57RcogX8/edit?usp=sharing)!
+
+Join the [Rebble Discord](https://discordapp.com/invite/aRUAYFN) #firmware-dev channel to discuss.
+### Architecture
+![CleanShot 2025-01-31 at 14 38 16@2x](https://github.com/user-attachments/assets/23d13a36-55e6-4e3a-87ab-4fb1fd1fca5a)
+
+![Arc 2025-01-31 11 44 47](https://github.com/user-attachments/assets/804bc6b9-47c1-4af5-b698-6078aca467ee)
+
+
 **WARNING**: Codebase is being refactored/modernized, so only certain features
 may work right now.