add example systemd service (#341)

example/gotosocial.service

@@ -0,0 +1,23 @@
+[Unit]
+Description=GoToSocial Server
+
+[Service]
+
+# make sure this user and group exist and have read and write permissions in your GoToSocial folder.
+# if they do not exist yet create them with "sudo useradd -r gotosocial"
+# then give them permission with "chown -R gotosocial:gotosocial /gotosocial" (path to your gotosocial folder)
+# you can adjust the users name according to your setup
+User=gotosocial
+Group=gotosocial
+
+Type=exec
+Restart=on-failure
+
+# change if your path to the GoToSocial binary is different
+ExecStart=/gotosocial/gotosocial --config-path config.yaml server start
+WorkingDirectory=/gotosocial
+
+[Install]
+WantedBy=default.target
+
+# After you are done editing this file move it to "/etc/systemd/system/gotosocial.service" and enable the service with "sudo systemctl enable --now gotosocial.service"