Merge pull request #1807 from xnaas/docs-touchup

update 'docker kill' command

distrib/docker/README.md

@@ -73,7 +73,7 @@ You can use the `/rehash` command to make Ergo reload its config, or
 send it the HUP signal:
 
 ```shell
-docker kill -HUP ergo
+docker kill -s SIGHUP ergo
 ```
 
 ## Using custom TLS certificates