docs: add banner image to README

Author: EchoBT

README.md

@@ -9,6 +9,8 @@
 [![GitHub stars](https://img.shields.io/github/stars/PlatformNetwork/platform)](https://github.com/PlatformNetwork/platform/stargazers)
 [![Rust](https://img.shields.io/badge/rust-1.90+-orange.svg)](https://www.rust-lang.org/)
 
+![Platform Banner](assets/banner.jpg)
+
 ![Alt](https://repobeats.axiom.co/api/embed/4b44b7f7c97e0591af537309baea88689aefe810.svg "Repobeats analytics image")
 
 </div>