Add / amend docs for using `avahi` advertiser from Docker
### Current Situation

The docs on the wiki for advertiser don't really provide information on how to configure homebridge to use `avahi` from a docker container if the host is already setup w/ `avahi`.

### Proposed Change

Add some aspect of (this is docker compose specific):

1. mount `dbus` and `avahi-daemon/socket` volumes to homebridge container
```
    volumes:
      - /opt/homebridge:/homebridge
      - /var/run/dbus:/var/run/dbus
      - /var/run/avahi-daemon/socket:/var/run/avahi-daemon/socket
```
2. disable (please enhance if there's a better way!) apparmor so container can use `dbus`
```
    security_opt:
      - apparmor:unconfined
```

### Additional Context

Without the `apparmor:unconfined`, I got errors like this:

```
