What is the lifecycle of a request?

I'm looking at adding a manifest.json file to a phoenix application to create a PWA. However the `mix phx.digest` creates alaready a cahce_manifest.json file in the `priv` directory.

At the moment it is not clear (or I forgot) what is the difference between the `assets` folder and the `priv` folder. I also need to remember how Phoenix render static assets and how the lifecycle of a request/response works with Phoenix.

- [ ] Add documentation in Readme how Phoenix manage assets

ref:
- https://hexdocs.pm/phoenix/Phoenix.Endpoint.html
- https://www.netguru.com/blog/phoenix-framework-request-response-life-cycle