[Docs] Added a service configuration and a process management section to the readme. (See #9)

### ArchLinux Packaging

## Configuration

### Service

The [avm-motion-triggerd](wikis/man/avm-motion-triggerd.1.html) daemon can be

configured with a configuration file which follows the format which is

described by the

[avm-motion-trigger.conf](wikis/man/avm-motion-trigger.conf.5.html) man page.

On ArchLinux the system wide configuration can be found at

`/etc/avm-motion-trigger.conf`.

### Process management

The [avm-motion-triggerd](wikis/man/avm-motion-triggerd.1.html) daemon can be

started in different flavors. It is able to run in foreground by adding the

`-f|--foreground` parameters or in background (without additional parameters).

While the daemon is running in foreground, all logging outputs will be printed

to `stdout` and/or `stderr`. The foreground logging is prefixed with the

current date/time and the log level for the message. While the daemon runs in

background, all logging outputs will be redirected to `syslog`.  For ArchLinux

there is a systemd unit file shipped for the daemon. The service can be enabled

with: `sudo systemctl enable avm-motion-triggerd.service`.

## Development