compose/reference: use "console" for shell examples

This allows for easier copying of the commands, without selecting the
prompt.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

compose/reference/ps.md

@@ -17,7 +17,7 @@ Options:
 
 Lists containers.
 
-```bash
+```console
 $ docker-compose ps
          Name                        Command                 State             Ports
 ---------------------------------------------------------------------------------------------

compose/reference/pull.md

@@ -38,7 +38,7 @@ services:
 
 If you run `docker-compose pull ServiceName` in the same directory as the `docker-compose.yml` file that defines the service, Docker pulls the associated image. For example, to call the `postgres` image configured as the `db` service in our example, you would run `docker-compose pull db`.
 
-```bash
+```console
 $ docker-compose pull db
 Pulling db (postgres:latest)...
 latest: Pulling from library/postgres

compose/reference/top.md

@@ -11,7 +11,7 @@ Usage: top [SERVICE...]
 
 Displays the running processes.
 
-```bash
+```console
 $ docker-compose top
 compose_service_a_1
 PID    USER   TIME   COMMAND