add example services file to run program at bootup

Change-Id: Id245640eb7d5026a9dc73d5bcbd8ee76140c6d63
diff --git a/examples/detect_faces.service b/examples/detect_faces.service
new file mode 100644
index 0000000..7468e35
--- /dev/null
+++ b/examples/detect_faces.service
@@ -0,0 +1,12 @@
+[Unit]
+Description=Face Detection example
+
+[Service]
+Environment=DISPLAY=:0
+Type=simple
+Restart=on-failure
+User=pi
+ExecStart=/usr/bin/python3 /home/pi/aiy-maker-kit/examples/detect_faces.py
+
+[Install]
+WantedBy=multi-user.target
\ No newline at end of file