Write replacement for Azure deployment guide

[sfc-gh-dmatthews]

The Azure deployment guide from Toward Data Science was moved behind a paywall on Medium and thus removed. A suggested replacement is https://learn.microsoft.com/en-us/answers/questions/1470782/how-to-deploy-a-streamlit-application-on-azure-app, but this appears to be somewhat informal.

We should write or find a more formal replacement.