Adds pause and unpause-commands

Signed-off-by: Frank Sachsenheim <funkyfuture@riseup.net>

docs/reference/docker-compose.md

@@ -28,6 +28,7 @@ Commands:
   help               Get help on a command
   kill               Kill containers
   logs               View output from containers
+  pause              Pause services
   port               Print the public port for a port binding
   ps                 List containers
   pull               Pulls service images
@@ -37,6 +38,7 @@ Commands:
   scale              Set number of containers for a service
   start              Start services
   stop               Stop services
+  unpause            Unpause services
   up                 Create and start containers
   migrate-to-labels  Recreate containers to add labels
 ```