Merge branch 'fig-info' into 'master'

information about why we use fig.yml

Because of tweet https://twitter.com/nicholasruunu/status/619533541605539841

cc/ @sytses @ayufan

See merge request !960

docker/README.md

@@ -94,12 +94,12 @@ To upgrade GitLab to new version you have to do:
 sudo docker stop gitlab
 ```
 
-1. stop running container, 
+1. stop running container,
 ```bash
 sudo docker rm gitlab
 ```
 
-1. remove existing container, 
+1. remove existing container,
 ```bash
 sudo docker pull gitlab/gitlab-ce:latest
 ```
@@ -162,4 +162,6 @@ sudo docker push gitlab/gitlab-ce:latest
 
 ## Troubleshooting
 
-Please see the [troubleshooting](troubleshooting.md) file in this directory.
\ No newline at end of file
+Please see the [troubleshooting](troubleshooting.md) file in this directory.
+
+Note: We use `fig.yml` to have compatibility with fig and because docker-compose also supports it.