Rename doc subdirectory to docs for higher consistency with OSS standards

docs/systemd-dbus-config.md

@@ -0,0 +1,54 @@
+Systemd and dbus configuration
+=======================
+
+**Table of contents**
+
+1. [Introduction](#introduction)
+2. [Systemd configuration](#systemd-configuration)
+3. [Dbus configuration](#dbus-configuration)
+
+Introduction
+------------
+
+To run executable as a systemd service you may need some additional setup. For example, you may need explicitly allow 
+the usage of your service. Following chapters contain template configurations.
+
+
+Systemd configuration
+---------------------------------------
+
+Filename should use `.service` extension. It also must be placed in configuration directory (/etc/systemd/system in
+Ubuntu 18.04.1 LTS) 
+
+```
+[Unit]
+Description=nameOfService
+
+[Service]
+ExecStart=/path/to/executable
+
+[Install]
+WantedBy=multi-user.target
+```
+
+Dbus configuration
+------------------
+
+Typical default D-Bus configuration does not allow to register services except explicitly allowed. Filename should 
+contain name of your service, e.g `/etc/dbus-1/system.d/org.sdbuscpp.concatenator.conf`. So, here is template
+configuration to use dbus interface under root:
+
+```
+<!DOCTYPE busconfig PUBLIC
+ "-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN"
+ "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
+<busconfig>
+  <policy user="root">
+    <allow own="org.sdbuscpp.concatenator"/>
+    <allow send_destination="org.sdbuscpp"/>
+    <allow send_interface="org.sdbuscpp.concatenator"/>
+  </policy>
+</busconfig>
+```
+
+If you need access from other user `root` should be substituted by desired username. For more refer to `man dbus-daemon`.