add screenshot docker container multi camera example

70_installation/80_Multi-camera/1_Docker.md

@@ -20,11 +20,24 @@ The approach is equal to [**the traditional Docker approach**](/installation/doc
         links:
         - machinery
 
-Instead of running docker-compose up, we add an additional parameter **-p**. This will create and link the containers from the compose file, but will **wrap and isolate** the containers **in a project**. By reusing this command, and defining different project names, you can run multiple Kerberos.io instances on the same machine (or distribute them over multiple machines.)
+Instead of running docker-compose up, we add an additional parameter **-p**. This will create and link the containers from the compose file, but will **wrap and isolate** the containers **in a project**. By reusing this command, and defining different project names, you can run multiple Kerberos.io instances on the same machine (or distribute them over multiple machines). Suppose that we want to start three containers:
 
-    docker-compose -p camera-frontdoor up -d
-    docker-compose -p camera-partyroom up -d
-    ...
-    docker-compose -p camera-garden up -d
+    $ docker-compose -p camera-frontdoor up -d
+    $ docker-compose -p camera-partyroom up -d
+    $ docker-compose -p camera-garden up -d
 
+If you type in the **docker ps** command, you'll get an overview of all the containers that are started; see a stripped output below. In the ports section you'll see the ports that have been exposed to access the web interface of each project.
 
+    $ docker ps
+
+    CONTAINER ID        IMAGE                CREATED             PORTS                            NAMES
+    30f74ea52852        kerberos/web         3 seconds ago       443/tcp, 0.0.0.0:32779->80/tcp   cameragarden_web_1
+    873d6bae8ea1        kerberos/machinery   5 seconds ago       0.0.0.0:32778->8889/tcp          cameragarden_machinery_1
+    439b3f7167fc        kerberos/web         7 seconds ago       443/tcp, 0.0.0.0:32777->80/tcp   camerapartyroom_web_1
+    9f8ed40c0d6e        kerberos/machinery   9 seconds ago       0.0.0.0:32776->8889/tcp          camerapartyroom_machinery_1
+    dc97a63ffc2d        kerberos/web         22 seconds ago      443/tcp, 0.0.0.0:32775->80/tcp   camerafrontdoor_web_1
+    1f3d6735405e        kerberos/machinery   23 seconds ago      0.0.0.0:32774->8889/tcp          camerafrontdoor_machinery_1
+
+If we want to connect to the web interface of the **cameragarden** container, we can open our browser and enter the url **http://your-ip:32779**.
+
+![Docker container example](1_docker.png)