Add a link to Docker's IPVS connection timeout docs for postgres

postgres/content.md

@@ -201,6 +201,8 @@ If there is no database when `postgres` starts in a container, then `postgres` w
 
 Also note that the default `/dev/shm` size for containers is 64MB. If the shared memory is exhausted you will encounter `ERROR:  could not resize shared memory segment . . . : No space left on device`. You will want to pass [`--shm-size=256MB`](https://docs.docker.com/engine/reference/run/#runtime-constraints-on-resources) for example to `docker run`, or alternatively in [`docker-compose`](https://docs.docker.com/compose/compose-file/#shm_size)
 
+See ["IPVS connection timeout issue" in the Docker Success Center](https://success.docker.com/article/ipvs-connection-timeout-issue) for details about IPVS connection timeouts which will affect long-running idle connections to PostgreSQL in Swarm Mode using overlay networks.
+
 ## Where to Store Data
 
 Important note: There are several ways to store data used by applications that run in Docker containers. We encourage users of the `%%IMAGE%%` images to familiarize themselves with the options available, including: