Tutorial for Daemons

[andreyluiz]

https://docs.rs/iced/latest/iced/daemon/struct.Daemon.html

This is a new feature introduced on 0.13. Unfortunately there's not a lot of documentation about it, but the examples are pretty good.

[fogarecious]

We could consider adding the example link to the 'See Also' section on the front page, or creating a tutorial page that demonstrates a simple example: starting a program, letting it run for a while, and then opening a window.