clarified installation process

examples/systemd/README.md

+# systemd .service files
+
+In Linux, these example systemd services will automatically start the Fadecandy server and one of the Python example scripts on boot.
+
+### Installation Procedure
+1. Ensure that the __fcserver__ executable resides in the directory specified in the .service file (/opt/fadecandy/server/ in this example)
+2. Copy the .service files into the /etc/systemd/system/ directory
+    ~~~
+    $ cp fadecandy.service example-leds.service /etc/systemd/system/
+    ~~~
+3. Enable the services
+    ~~~
+    $ systemctl enable fadecandy.service
+    $ systemctl enable example-leds.service
+    ~~~
+4. Start the services
+    ~~~
+    $ systemctl start fadecandy.service
+    $ systemctl start example-leds.service
+    ~~~