update docs/reference/commandline/network_inspect.md

The following sentences (introduced in v1.11 via #21160) were misleading for Swarm mode services (>= v1.12)

  For networks backed by multi-host network driver, such as Overlay,
  this command also shows the container endpoints in other hosts in the
  cluster. These endpoints are represented as "ep-{endpoint-id}" in the output.

Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>

docs/reference/commandline/network_inspect.md

@@ -39,6 +39,9 @@ The `network inspect` command shows the containers, by id, in its
 results. For networks backed by multi-host network driver, such as Overlay,
 this command also shows the container endpoints in other hosts in the
 cluster. These endpoints are represented as "ep-{endpoint-id}" in the output.
+However, for swarm-scoped networks, only the endpoints that are local to the
+node are shown.
+
 You can specify an alternate format to execute a given
 template for each result. Go's
 [text/template](http://golang.org/pkg/text/template/) package describes all the