📝 Link to deployment tutorial (#274)

docs/external-links.md

@@ -2,4 +2,6 @@
 
 External links related to using Mangum.
 
+- [Deploying Python web apps as AWS Lambda functions](https://til.simonwillison.net/awslambda/asgi-mangum) is a tutorial that goes through every step involved in packaging and deploying a Python web application to AWS Lambda, including how to use Mangum to wrap an ASGI application. 
+
 If you're interested in contributing to this page, please reference this [issue](https://github.com/jordaneremieff/mangum/issues/104) in a PR.