Project/code for flask api tutorial

https://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-i-hello-world

I've added some goodies, like gravatars.

This project was used to start teaching my son how to code, and for me to learn flask. We've both long moved on, so the code is stale. Maybe I'll look at it again some day.

This readme needs an uplift.