Mark figures' intended size

This commit activates Sass styling to make image sizes more responsive
on the rendered page.

content/en/docs/concepts/workloads/pods/_index.md

@@ -112,7 +112,7 @@ For example, you might have a container that
 acts as a web server for files in a shared volume, and a separate "sidecar" container
 that updates those files from a remote source, as in the following diagram:
 
-{{< figure src="/images/docs/pod.svg" alt="example pod diagram" width="50%" >}}
+{{< figure src="/images/docs/pod.svg" alt="Pod creation diagram" class="diagram-medium" >}}
 
 Some Pods have {{< glossary_tooltip text="init containers" term_id="init-container" >}} as well as {{< glossary_tooltip text="app containers" term_id="app-container" >}}. Init containers run and complete before the app containers are started.
 

content/en/docs/concepts/workloads/pods/pod-lifecycle.md

@@ -55,7 +55,7 @@ exists. If that Pod is deleted for any reason, and even if an identical replacem
 is created, the related thing (a volume, in this example) is also destroyed and
 created anew.
 
-{{< figure src="/images/docs/pod.svg" title="Pod diagram" width="50%" >}}
+{{< figure src="/images/docs/pod.svg" title="Pod diagram" class="diagram-medium" >}}
 
 *A multi-container Pod that contains a file puller and a
 web server that uses a persistent volume for shared storage between the containers.*