Add stop signal to the docs.

Signed-off-by: Daniel Nephin <dnephin@docker.com>

docs/compose-file.md

@@ -473,6 +473,14 @@ Override the default labeling scheme for each container.
       - label:user:USER
       - label:role:ROLE
 
+### stop_signal
+
+Sets an alternative signal to stop the container. By default `stop` uses
+SIGTERM. Setting an alternative signal using `stop_signal` will cause
+`stop` to send that signal instead.
+
+    stop_signal: SIGUSR1
+
 ### ulimits
 
 Override the default ulimits for a container. You can either specify a single

docs/index.md

@@ -45,8 +45,7 @@ A `docker-compose.yml` looks like this:
       redis:
         image: redis
     volumes:
-      logvolume01:
-        driver: default
+      logvolume01: {}
 
 For more information about the Compose file, see the
 [Compose file reference](compose-file.md)