feat(service): add systemd unit

ntfy-matrix-bridge.service

@@ -0,0 +1,19 @@
+[Unit]
+Description=ntfy -> Matrix bridge
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+User=ntfybridge
+WorkingDirectory=/opt/ntfy-matrix-bridge
+# Keep the token out of the config file by passing it in here (chmod 600 the
+# unit, or use an EnvironmentFile=/etc/ntfy-matrix-bridge.env instead).
+Environment=MATRIX_ACCESS_TOKEN=replace-me
+# EnvironmentFile=/etc/ntfy-matrix-bridge.env
+ExecStart=/opt/ntfy-matrix-bridge/venv/bin/python /opt/ntfy-matrix-bridge/bridge.py --config /opt/ntfy-matrix-bridge/config.yaml
+Restart=on-failure
+RestartSec=5
+
+[Install]
+WantedBy=multi-user.target