add an example systemd unit file

contrib/README

@@ -1,6 +1,12 @@
-This directory is for additional contributed files which may be useful.
+This directory is for additional contributed files which may be
+useful.
+
+gmid.service
+
+	Simple systemd service file.
 
 vim
 
 	Syntax highlighting of gmid configuration for vim, to be
 	placed into ~/.vim/ or /usr/share/vim/vimfiles.
+

contrib/gmid.service

@@ -0,0 +1,14 @@
+[Unit]
+Description=The gmid Gemini server
+After=syslog.target network.target
+Wants=network-online.target
+
+[Service]
+Type=forking
+ExecStart=/usr/local/bin/gmid -c /etc/gmid.conf
+# to start the daemon as a dedicated user:
+#User=_gmid
+#Group=_gmid
+
+[Install]
+WantedBy=multi-user.target