chore: add example start

Author: gjrtimmer

examples/repmgr/start.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+if ! docker network ls --format '{{.Name}}' | grep -q "synohub" -; then
+  docker network create --subnet=172.50.0.0/16 --ip-range=172.50.50.1/24 --gateway=172.50.0.1 psql-playground
+fi
+
+PUID=$(id -u) PGID=$(id -g) docker-compose up -d