expand/collapse accordion full implementation, explanation in test.md

Signed-off-by: Victoria Bialas <victoria.bialas@docker.com>

_scss/_utilities.scss

@@ -62,6 +62,19 @@ img.inline {
     display: inline;
 }
 
+.panel-heading .chevron:after {
+    content: "\f0d8";
+}
+
+.panel-heading.collapsed .chevron:after {
+    content: "\f0d7";
+}
+
+.panel-heading:hover{
+    background: #fafdfe;
+}
+
+
 /*
 * Search *********************************************************************
 *

compose/compose-file/index.md

@@ -46,111 +46,105 @@ topic on [Deploying an app to a
 Swarm](https://github.com/docker/labs/blob/master/beginner/chapters/votingapp.md).
 Click to show/hide the example Compose file below.
 
-<div class="panel-group" id="accordion" role="tablist" aria-multiselectable="true">
-
-  <div class="panel panel-default">
-    <div class="panel-heading" role="tab" id="headingThree">
-      <h5 class="panel-title" id="collapsible-group-item-3"> <a class="" role="button" data-toggle="collapse" data-parent="#accordion" data-target="#collapseThree" aria-expanded="true" aria-controls="collapseThree"> Example Compose file version 3 <i class="fa fa-chevron-down"></i></a> </h5>
-    </div>
-    <div id="collapseThree" class="panel-collapse collapse" role="tabpanel" aria-labelledby="headingThree" aria-expanded="true">
-      <div class="panel-body">
-      <pre><code>
+<div class="panel panel-default">
+    <div class="panel-heading collapsed" data-toggle="collapse" data-target="#collapseSample1">
+    Example Compose file version 3
+    <i class="chevron fa fa-fw"></i></div>
+    <div class="collapse block" id="collapseSample1">
+<pre><code>
 version: "3"
 services:
 
-  redis:
-    image: redis:alpine
-    ports:
-      - "6379"
-    networks:
-      - frontend
-    deploy:
-      replicas: 2
-      update_config:
-        parallelism: 2
-        delay: 10s
-      restart_policy:
-        condition: on-failure
-  db:
-    image: postgres:9.4
-    volumes:
-      - db-data:/var/lib/postgresql/data
-    networks:
-      - backend
-    deploy:
-      placement:
-        constraints: [node.role == manager]
-  vote:
-    image: dockersamples/examplevotingapp_vote:before
-    ports:
-      - 5000:80
-    networks:
-      - frontend
-    depends_on:
-      - redis
-    deploy:
-      replicas: 2
-      update_config:
-        parallelism: 2
-      restart_policy:
-        condition: on-failure
-  result:
-    image: dockersamples/examplevotingapp_result:before
-    ports:
-      - 5001:80
-    networks:
-      - backend
-    depends_on:
-      - db
-    deploy:
-      replicas: 1
-      update_config:
-        parallelism: 2
-        delay: 10s
-      restart_policy:
-        condition: on-failure
-
-  worker:
-    image: dockersamples/examplevotingapp_worker
-    networks:
-      - frontend
-      - backend
-    deploy:
-      mode: replicated
-      replicas: 1
-      labels: [APP=VOTING]
-      restart_policy:
-        condition: on-failure
-        delay: 10s
-        max_attempts: 3
-        window: 120s
-      placement:
-        constraints: [node.role == manager]
-
-  visualizer:
-    image: dockersamples/visualizer:stable
-    ports:
-      - "8080:8080"
-    stop_grace_period: 1m30s
-    volumes:
-      - "/var/run/docker.sock:/var/run/docker.sock"
-    deploy:
-      placement:
-        constraints: [node.role == manager]
+redis:
+  image: redis:alpine
+  ports:
+    - "6379"
+  networks:
+    - frontend
+  deploy:
+    replicas: 2
+    update_config:
+      parallelism: 2
+      delay: 10s
+    restart_policy:
+      condition: on-failure
+db:
+  image: postgres:9.4
+  volumes:
+    - db-data:/var/lib/postgresql/data
+  networks:
+    - backend
+  deploy:
+    placement:
+      constraints: [node.role == manager]
+vote:
+  image: dockersamples/examplevotingapp_vote:before
+  ports:
+    - 5000:80
+  networks:
+    - frontend
+  depends_on:
+    - redis
+  deploy:
+    replicas: 2
+    update_config:
+      parallelism: 2
+    restart_policy:
+      condition: on-failure
+result:
+  image: dockersamples/examplevotingapp_result:before
+  ports:
+    - 5001:80
+  networks:
+    - backend
+  depends_on:
+    - db
+  deploy:
+    replicas: 1
+    update_config:
+      parallelism: 2
+      delay: 10s
+    restart_policy:
+      condition: on-failure
+
+worker:
+  image: dockersamples/examplevotingapp_worker
+  networks:
+    - frontend
+    - backend
+  deploy:
+    mode: replicated
+    replicas: 1
+    labels: [APP=VOTING]
+    restart_policy:
+      condition: on-failure
+      delay: 10s
+      max_attempts: 3
+      window: 120s
+    placement:
+      constraints: [node.role == manager]
+
+visualizer:
+  image: dockersamples/visualizer:stable
+  ports:
+    - "8080:8080"
+  stop_grace_period: 1m30s
+  volumes:
+    - "/var/run/docker.sock:/var/run/docker.sock"
+  deploy:
+    placement:
+      constraints: [node.role == manager]
 
 networks:
-    frontend:
-    backend:
+  frontend:
+  backend:
 
 volumes:
-    db-data:
-    </code></pre>
-      </div>
+  db-data:
+</code></pre>
     </div>
-  </div>
 </div>
 
-
 ## Service configuration reference
 
 The Compose file is a [YAML](http://yaml.org/) file defining