Updating Compose documentation

- Split out commands into individual pages for maintainability
- Add full usage in commands pages for usability
- Updated description of the run command
- adding in Aanand's comment

Signed-off-by: Mary Anthony <mary@docker.com>

docs/reference/overview.md

@@ -0,0 +1,68 @@
+<!--[metadata]>
++++
+title = "Introduction to the CLI"
+description = "Introduction to the CLI"
+keywords = ["fig, composition, compose, docker, orchestration, cli,  reference"]
+[menu.main]
+parent = "smn_compose_cli"
+weight=-2	
++++
+<![end-metadata]-->
+
+
+# Introduction to the CLI
+
+This section describes the subcommands you can use with the `docker-compose` command.  You can run subcommand against one or more services. To run against a specific service, you supply the service name from your compose configuration. If you do not specify the service name, the command runs against all the services in your configuration.
+
+## Environment Variables
+
+Several environment variables are available for you to configure the Docker Compose command-line behaviour.
+
+Variables starting with `DOCKER_` are the same as those used to configure the
+Docker command-line client. If you're using `docker-machine`, then the `eval "$(docker-machine env my-docker-vm)"` command should set them to their correct values. (In this example, `my-docker-vm` is the name of a machine you created.)
+
+### COMPOSE\_PROJECT\_NAME
+
+Sets the project name. This value is prepended along with the service name to the container container on start up. For example, if you project name is `myapp` and it includes two services `db` and `web` then compose starts containers named  `myapp_db_1` and `myapp_web_1` respectively.
+
+Setting this is optional. If you do not set this, the `COMPOSE_PROJECT_NAME` defaults to the `basename` of the current working directory.
+
+### COMPOSE\_FILE
+
+Specify the file containing the compose configuration. If not provided, Compose looks for a file named  `docker-compose.yml` in the current directory and then each parent directory in succession until a file by that name is found.
+
+### DOCKER\_HOST
+
+Sets the URL of the `docker` daemon. As with the Docker client, defaults to `unix:///var/run/docker.sock`.
+
+### DOCKER\_TLS\_VERIFY
+
+When set to anything other than an empty string, enables TLS communication with
+the `docker` daemon.
+
+### DOCKER\_CERT\_PATH
+
+Configures the path to the `ca.pem`, `cert.pem`, and `key.pem` files used for TLS verification. Defaults to `~/.docker`.
+
+### COMPOSE\_MAX\_WORKERS
+
+Configures the maximum number of worker threads to be used when executing
+commands in parallel. Only a subset of commands execute in parallel, `stop`,
+`kill` and `rm`.
+
+
+
+
+
+
+
+## Compose documentation
+
+- [User guide](/)
+- [Installing Compose](install.md)
+- [Get started with Django](django.md)
+- [Get started with Rails](rails.md)
+- [Get started with Wordpress](wordpress.md)
+- [Yaml file reference](yml.md)
+- [Compose environment variables](env.md)
+- [Compose command line completion](completion.md)