rycus86/demo-site

We can see on the high-level overview that there are three main types of interaction
between the frontend and the backend:

- `HTTP GET` requests from the browser to load the *HTML* generated by the **demo-site** app
- `HTTP POST` requests with *JSON* payload from *jQuery* to render *HTML* fragments 
  using another **demo-site** endpoint
- `HTTP GET` to one of the three **proxy** apps to get the *JSON* required for the fragment above

Each request will end up on the **nginx** proxy server that is the only application in the
stack listening to requests from the external network.
It's configuration is managed by **nginx-pygen** for the backend services and by
**certbot-pygen** for the SSL certificates.