Add coolify to section serverless (#3348)

README.md

@@ -1775,6 +1775,7 @@ Software for easy installation, management and configuration of self-hosted serv
 [Serverless computing - Wikipedia](https://en.wikipedia.org/wiki/Serverless_computing).
 
 - [Appwrite](https://appwrite.io) - End to end backend server for web, native, and mobile developers 🚀. ([Source Code](https://github.com/appwrite/appwrite)) `BSD-3-Clause` `PHP`
+- [Coolify](https://coolify.io/) - An open-source & self-hostable Heroku / Netlify alternative (and even more). ([Demo](https://demo.coolify.io/), [Source Code](https://github.com/coollabsio/coolify)) `Apache-2.0` `Docker`
 - [fx](https://github.com/metrue/fx) - A tool to help you do Function as a Service with painless on your own servers. `MIT` `Go`
 - [IronFunctions](https://github.com/iron-io/functions) - The serverless microservices platform by [iron.io](https://www.iron.io/). `Apache-2.0` `Go`
 - [LocalStack](https://localstack.cloud/) - LocalStack is a fully functional local AWS cloud stack. This includes Lambda for serverless computation. ([Source Code](https://github.com/localstack/localstack)) `Apache-2.0` `Python/Other`