docs: remove walkthrough from README

Removing code walkthrough as the video is no longer available on Twitch 🥲

Author: nmoutschen

README.md

@@ -10,10 +10,6 @@ This is a simple serverless application built in Rust. It consists of an API Gat
 
 This single crate will create [five different binaries](./src/bin), one for each Lambda function. It uses an [hexagonal architecture pattern](https://aws.amazon.com/blogs/compute/developing-evolutionary-architecture-with-aws-lambda/) to decouple the [entry points](./src/entrypoints/), from the main [domain logic](./src/lib.rs), the [storage component](./src/store), and the [event bus component](./src/event_bus).
 
-### Code walkthrough
-
-If you want to learn more about Rust on Lambda and how this project is structured, you can find a recorded walkthrough on [the AWS Twitch channel](https://www.twitch.tv/videos/1201473601).
-
 ## 🏗️ Deployment and testing
 
 ### Requirements