Write replacement for AWS deployment guide

The AWS deployment guide from [Toward Data Science](https://towardsdatascience.com/how-to-deploy-a-streamlit-app-using-an-amazon-free-ec2-instance-416a41f69dc3) was moved behind a paywall on [Medium](https://medium.com/data-science/how-to-deploy-a-streamlit-app-using-an-amazon-free-ec2-instance-416a41f69dc3) and thus removed.

We should write or find a more formal replacement.