UwULock Server 0.0.2

A reverse proxy in a container. Behind a proxy that runs as a Docker container on the same
machine, the server listened on 127.0.0.1 — which inside the proxy's container is the proxy
itself, so it answered 502.

• install.sh --proxy-network NET puts the server into the proxy's Docker network instead of
  onto a port of the machine; the proxy reaches it at http://uwulock:8443. Asked for, too, when
  you choose the proxy without flags. A port on the machine that something else has already, like
  8443, no longer matters then.
• --proxy-ip ADDRESS gives it a fixed address in that network, which ipvlan and macvlan
  networks need: the proxy passes on to http://ADDRESS:8443.
• The address the proxy has to pass on to, and the lines for Caddy, are printed at the end.
• How it looks by hand, as a compose.override.yaml: docs/deployment.md.